1. A contact lens package, comprising: a cavity; a cast molded contact lens disposed in the cavity, wherein the contact lens comprises a reaction product of a polymerizable composition comprising polyvinyl pyrrolidone, at least one hydrophilic monomer, and at least one cross-linking monomer reactive with the at least one hydrophilic monomer; a surfactant-free liquid disposed in the cavity and in contact with the contact lens, the liquid including polyvinyl pyrrolidone; and a seal surrounding the cavity to maintain the contact lens in a sterile environment.

2. The package of claim 1, wherein the contact lens is a hydrogel-containing contact lens.

3. The package of claim 1, wherein the contact lens includes a hydrophilic polymeric material and the polyvinyl pyrrolidone is present in the contact lens in an amount of about 1% to about 50% by weight of the hydrophilic polymeric material.

4. The package of claim 1, wherein the contact lens includes a hydrophilic polymeric material and the polyvinyl pyrrolidone is present in the contact lens in an amount of about 5% to about 40% by weight of the hydrophilic polymeric material.

5. The package of claim 1, wherein the contact lens includes a hydrophilic polymeric material and the polyvinyl pyrrolidone is present in the contact lens in an amount of about 10% to about 30% by weight of the hydrophilic polymeric material.

6. The package of claim 1, wherein the contact lens comprises at least two water soluble polymers.

7. The package of claim 6, wherein one of the water soluble polymers is polyethylene glycol.

8. The package of claim 1, Therein the liquid is an aqueous liquid.

9. The package of claim 1, wherein the liquid comprises a saline solution.

10. The package of claim 1, wherein the liquid comprises a buffered saline solution.

11. The package of claim 1, wherein the package is sterilized.

12. The package of claim 1, wherein the contact lens is a single use contact lens.

13. The package of claim 1, wherein the contact lens comprises a hydrophilic polymer including at least one monomer selected from the group consisting of hydroxalkyl acrylates, hydroxyalkyl methacrylates, N-vinyl pyrrolidone, acrylamides, vinyl alcohol, hydrophilic polyurethane precursors, glycerol acrylates, glycerol methacrylates, acrylates methacrylates, and mixtures thereof.

14. A contact lens package, comprising: a cavity; a cast molded contact lens disposed in the cavity, wherein the contact lens comprises a reaction product of a polyrmerizable composition comprising polyvinyl pyrrolidone and at least one monomer; a liquid disposed in the cavity and in contact with the contact lens, the liquid including polyvinyl pyrrolidone in an amount effective in reducing migration of the polyvinyl pyrrolidone present in the contact lens from the contact lens into the liquid in the cavity; and a seal surrounding the cavity to maintain the contact lens in a sterile environment.
Contact Lens Description
FIELD

The present invention relates to hydrogel-containing contact lenses, packaging systems including same and methods of producing same. More particularly the invention relates to hydrogel-containing contact lenses, for example, disposable contact lenses, including water soluble polymer components, and packaging systems for use with same and methods of producing same.

BACKGROUND

In the recent past, a method for producing hydrogel-containing contact lenses has been developed which is more economical than either lathe cutting or spin casting, and provides better control over the final shape of the hydrated lens. This method involves direct molding of a monomer mixture wherein said mixture is dissolved in a non-aqueous, displaceable solvent. The mixture is placed in a mold having the precise shape of the final desired hydrogel (i.e., water-swollen) lens, and the monomer/solvent mixture is subjected to conditions whereby the monomer(s) polymerize, to thereby produce a polymer/solvent mixture in the shape of the final desired hydrogel lens.

After the polymerization is complete, the solvent is displaced with water to produce a hydrated lens whose final size and shape are quite similar to the size and shape of the original molded polymer/solvent article.

Such direct molding of hydrogel contact lenses is disclosed in Larsen, U.S. Pat. No. 4,495,313 and in Larsen et al., U.S. Pat. Nos. 4,680,336, 4,889,664 and 5,039,459. In addition, other patents to be considered include Larson U.S. Pat. No. 4,565,348; Okkada et al U.S. Pat. No. 4,347,198; Shepherd U.S. Pat. No. 4,208,364; Mueller et al EP-A-0493,320A2; and Wichterle et al U.S. Pat. No. RE 27,401 (U.S. Pat. No. 3,220,960). The disclosure of each of these patents is incorporated in its entirety herein by reference.

It would be advantageous to provide new and beneficial hydrogel-containing contact lenses, packaging systems for such lenses and methods of producing such contact lenses.

SUMMARY

New hydrogel-containing contact lenses, packaging systems for use with such lenses and methods of producing such lenses have been discovered. The present hydrogel-containing lenses take advantage of the economies and shape control benefits of direct molding of hydrogel-containing contact lenses. In addition, by properly selecting the diluent or material included in the mold during lens formation, in particular by employing one or more water soluble polymer components, such diluent or material may remain within the lens ready for use in an eye. Thus, the present methods of making hydrogel-containing contact lenses are even less complex and more economical, for example, by eliminating the solvent displacing step, relative to prior art direct molding processes discussed elsewhere herein. The present packaging systems advantageously maintain the diluent or material in the contact lenses prior to use in an eye. In addition, the hydrogel-containing lenses advantageously have increased modulus or strength when first placed in an eye. Over time, for example, over a one day use period, the diluent or material is removed from the lens and replaced by water or tear fluid in the eye. When the lens is removed from the eye, it has less strength and provides an indication to the wearer that the lens should be disposed of and replaced. In addition, should the wearer use the lens again, the lens would be less comfortable to wear, for example, due to the loss of the diluent or material. This reduced comfort feature provides an indication to the wearer that the lens should be disposed of and replaced. The present lenses are particularly advantageous when provided as disposable lenses, for example, lenses suitable or structured for one time usage.

In one broad aspect, the present invention is directed to contact lenses which comprise contact lens bodies. The contact lens bodies comprise a hydrophilic polymeric material and a water soluble polymer component (WSPC). Such contact lens bodies are ready for use in an eye. In one embodiment, the WSPC is in intimate admixture with the hydrophilic polymeric material.

In a very useful embodiment, the WSPC is derived from a diluent material used during polymerization of the hydrophilic polymeric material. The WSPC advantageously is derived from a diluent material, for example, is at least a portion of the diluent material, used during solution polymerization of a hydrophilic polymeric material.

In one embodiment, the contact lens body is produced using wet cast molding.

As noted above, the present contact lenses advantageously are structured to be disposed of after a single use in the eye.

The present contact lens bodies including the WSPCs preferably have increased modulus relative to identical lens bodies in which the WSPC is replaced with water.

The WSPC advantageously is physically immobilized by the hydrophilic polymeric material in the present contact lens bodies. For example, the WSPC and the hydrophilic polymeric material may form an interpenetrating network or a pseudo interpenetrating network, preferably a pseudo interpenetrating network, in the lens body.

The present contact lens bodies preferably are configured or structured so that at least a portion of the WSPC leaves or is removed from the contact lens body during use of the contact lens body in an eye.

The hydrophilic polymeric material preferably is obtained by polymerization of at least one monomeric component, for example, by the polymerization of at least one hydrophilic monomeric component and at least one cross-linking monomeric component.

The hydrophilic monomeric component may be selected from any suitable such component. In a very useful embodiment, the hydrophilic monomeric component is selected from hydroxyalkyl acrylates, hydroxyalkyl methacrylates, N-vinyl pyrrolidone, acrylamides, vinyl alcohol, hydrophilic polyurethane precursors, glycerol acrylates, glycerol methacrylates, acrylates, methacrylates, substituted counterparts thereof and the like and mixtures thereof.

As used herein, the term “substituted counterparts thereof” refers to entities, e.g., compounds, which include one or more substituents and are effective to function in the present invention substantially like the unsubstituted entities, for example, the compounds listed herein.

Any suitable WSPC may be employed provided that it is effective in the present contact lenses, as described herein.

In one embodiment, the monomeric components from which the WSPCs are derived, for example, at least one ethylenically unsaturated hydrophilic monomeric component, are polymerizable to form linear or branched chain water soluble polymers or copolymers.

Hydrophilic monomeric components suitable for production of the WSPCs include, but are not limited to, hydrophilic vinylic monomers, such as vinyl (C.sub.4-C.sub.45)alkyl ethers, vinyl (C.sub.7-C.sub.49) alkenoic acids and the like and mixtures thereof; hydroxy substituted (C.sub.5-C.sub.45)alkyl, alkoxy-alkyl and polyalkoxy-alkyl and mono- or bi-cycloaliphatic fumarates, maleates, acrylates, methacrylates, acrylamides and methacrylamides, and the like and mixtures thereof; acrylic acid, methacrylic acid, the corresponding amino or mono- and di-(lower alkyl)amino substituted acrylic monomers and the like and mixtures thereof; and vinyl-lactams and the like and mixtures thereof. Typical monomers include, but are not limited to, 2-hydroxyethyl, 2-hydroxypropyl, and 3-hydroxypropyl acrylates and methacrylates; N-vinylpyrrolidone; N,N-dimethylaminoethyl methacrylate; methoxyethyl-, ethoxyethyl, methoxy-ethoxyethyl and ethoxy-ethoxyethyl acrylates and methacrylates; (meth)acrylamides like N,N-dimethyl, N,N-diethyl, 2-hydroxyethyl-, 2-hydroxypropyl-, and 3-hydroxypropyl acrylamides and methacrylamides; vinyl sulfonic acid; styrene sulfonic acid; 2-methacrylamide-2-methyl propane-sulfonic acid and the like and mixtures thereof.

In one embodiment, the WSPC preferably includes units derived from one or more of acrylic acid, hydrophilic derivatives of acrylic acid, methacrylic acid, hydrophilic derivatives of methacrylic acid, cationic/anionic pairs of monomeric components, cationic monomeric components, anionic monomeric components, nonionic monomeric components, hydrophilic vinylic monomeric components, salts thereof and mixtures thereof.

In one very useful embodiment, the WSPC is selected from polyalkylene glycols, for example, polyethylene glycols, polypropylene glycols and the like, polyvinyl pyrrolidone, polymethacrylic acid, polyvinyl alcohol, and the like and mixtures thereof.

In another broad aspect of the present invention, packaging systems are provided which comprise a contact lens ready for use in an eye, a liquid medium, and a container holding the contact lens and the liquid medium. The contact lens comprises a contact lens body including a hydrophilic polymeric material and a WSPC, as described elsewhere herein. The liquid medium, preferably an aqueous liquid medium, comprises an amount of the WSPC in addition to that present in the contact lens body.

The liquid medium preferably includes the WSPC prior to the liquid medium being placed in the container, for example, in contact, with the contact lens.

Advantageously, the container is sealed, for example, using any suitable conventional container seal assembly, such as a conventional container seal assembly, and preferably sterilized to protect, preserve and maintain sterilized the contact lens and the liquid medium during shipment and storage.

In a further broad aspect of the present invention, methods for producing contact lenses are provided. Such methods comprise polymerizing at least one hydrophilic monomeric component in the presence of a WSPC to form a contact lens body comprising a hydrophilic polymeric material and the WSPC. Advantageously, an effective amount of at least one cross-linking monomeric component is present during the polymerizing step. The contact lens body is placed in a packaging container, preferably in a packaging system as described elsewhere herein.

Advantageously the polymerizing step is a solution polymerizing step. The WSPC preferably is included in a diluent used during the polymerizing step. The polymerizing step preferably occurs in a contact lens mold, for example, a conventional contact lens mold, such as a conventional thermoplastic contact lens mold.

In one very useful embodiment, a liquid medium, preferably an aqueous liquid medium, is also placed in the packaging container. This liquid medium preferably includes an amount of the WSPC in addition to that present in the contact lens body. The WSPC and the liquid medium preferably are ophthalmically acceptable.

In addition, the present methods preferably further comprise sealing the container with a contact lens body, and preferably the liquid medium, included therein.

Each and every feature described herein, and each and every combination of two or more of such features, is included within the scope of the present invention provided that the features included in such a combination are not mutually inconsistent.

These and other aspects of the present invention are set forth in the following detailed description, examples and claims, particularly when considered in conjunction with the accompanying drawings in which like parts bear like reference numerals.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of a packaging system in accordance with the present invention.

DETAILED DESCRIPTION

The present contact lenses comprise a contact lens body comprising a hydrophilic polymeric material and a WSPC, preferably an effective amount of the WSPC, for example, to increase the modulus or strength of the contact lens and/or to provide enhanced lubrication to the eye wearing the contact lens and/or to increase the comfort to the lens wearer of wearing the contact lens. Such benefits, e.g., increases and/or enhancements, are relative to an identical contact lens without the WSPC.

The hydrophilic polymeric materials useful in the present contact lenses may be selected from any suitable such materials. Preferably, such hydrophilic polymeric materials are such as to take on or absorb sufficient water so as to expand or swell. Such water-swellable materials are often referred to as hydrogels. A number of hydrophilic polymeric materials are conventionally used in contact lenses, and such conventionally used materials may be employed in the present contact lenses. Specific examples, without limitation, of useful hydrophilic polymeric materials are identified elsewhere herein.

An important feature of the present invention is the inclusion of WSPCs in the present contact lenses.

The WSPCs useful in the present invention may be chosen from any suitable such components. The presently useful WSPCs advantageously are ophthalmically acceptable and substantially not cytotoxic.

In a very useful embodiment, the WSPC is effective to provide at least one benefit to the contact lens and/or to the wearing of the contact lens and/or to the wearer of the contact lens. For example, the WSPC advantageously is present in an amount effective to increase the modulus or strength of the contact lens relative to an identical contact lens in which the WSPC is replaced by water. The WSPC may be selected, and present in the contact lens in an amount, so as to be effective as a lubricant or lubricity agent as the WSPC dissolves into the tear fluid while the contact lens is in use in an eye. Thus, the lens wearer’s eye, for example, cornea and/or eyelids, is more effectively lubricated when wearing the present contact lenses, which enhances the comfort of wearing the lenses, relative to an identical contact lens in which the WSPC is replaced by water.

The WSPC may be selected to have substantially no detrimental effect on the optical clarity and/or optical power of the contact lens while in use.

Specific examples, without limitation, of useful WSPCs are identified elsewhere herein. The XVSPC ma be included in the present contract lenses in any suitable amount effective to provide the desired result. Such amounts may be in a range of about 1% or about 5% or about 10% or about 15% to about 20% or about 30% or about 40% or about 50% or more of the hydrophilic polymeric material present in the contact lens.

One very useful class of WSPCs include polyethylene glycols. Polyethylene glycols are compounds that can be represented by the following formula: HO–(CH.sub.2–CH.sub.2O).sub.n–H wherein n represents a number such that the molecular weight of the polyethylene glycol is within the range of from about 300 to about 10,000 and preferably from about 400 to about 2000 or about 5000. Such polyethylene glycols are commercially available products.

The WSPCs employed are ultimately water-displaceable. That is, after placing the contact lens including the hydrophilic polymeric material and the WSPC in the eye, the WSPC is ultimately at least partially, and even substantially completely, replaced with water in the eye.

However, it is advantageous to provide the WSPCs in the present contact lenses so that the hydrophilic polymeric material physically immobilizes the WSPC, at least to a limited extent. For example, the hydrophilic polymeric material may immobilize the WSPC in the contact lens sufficiently so that the WSPC is replaced by water substantially only after the lens is placed in an eye. In one useful embodiment, the WSPC is present in the present contact lenses in an interpenetrating network or pseudo penetrating network with the hydrophilic polymeric material, for example, to provide the desired degree of physical immobilization of the WSPC.

The replacement, for example, controlled replacement, of the WSPC by water in the eye, can allow the WSPC, in the eye, to provide added lubrication and comfort to the lens wearer. In addition, the removal of the WSPC from the contact lens in the eye may reduce the modulus or strength of the lens. Thus, after the lens wearer removes the WSPC-depleted lens from his/her eye, the lens will have different strength properties than before it was placed in the eye. These different properties provide an indication to the wearer that the lens is to be disposed of, rather than to be reused. In other words, the replacement of the WSPC in the contact lens with water in the eye, advantageously facilitates lens wearer compliance with proper usage of disposable contact lenses. The present lenses preferably are structured to be disposed of after a single use in the eye.

Mixtures of two or more WSPCs may be included in a single contact lens in accordance with the present invention.

The hydrophilic polymeric material employed in the present contact lenses may be derived from any suitable monomer or mixture of monomers. In one embodiment, a monomer mixture used which contains a major proportion of at least one hydrophilic monomer such as 2-hydroxyethyl methacrylate (”HEMA”) as the major component, one or more cross-linking monomers, and optionally small amounts of other monomers such as methacrylic acid. HEMA is one preferred hydrophilic monomer. Other hydrophilic monomers that can be employed include, without limitation, 2-hydroxyethyl acrylate, 2-hydroxypropyl methacrylate, 2-hydroxypropyl acrylate, 3-hydroxypropyl methacrylate, N-vinyl pyrrolidone, glycerol mono-methacrylate, glycerol mono-acrylate, and the like and mixtures thereof.

The cross-linking monomers that can be employed, either singly or in combination, include, without limitation, ethylene glycol dimethacrylate (”EGDMA”), trimethylolpropane trimethacrylate (”TMPTMA”), glycerol trimethacrylate, polyethylene glycol dimethacrylate (wherein the polyethylene glycol has a molecular weight up to, for example, about 5000), other polyacrylate and polymethacrylate esters, end-capped polyoxyethylene polyols containing two or more terminal methacrylate moieties and the like and mixtures thereof. The cross-linking monomer is used in the usual amounts, e.g., from about 0.01% or less to about 0.5% or more, by weight of the reactive monomer mixture. The cross-linking monomer can be a hydrophilic monomer.

Other monomers that can be used include methacrylic acid, which is used to influence the amount of water that the hydrophilic polymeric material absorbs at equilibrium. Methacrylic acid is usually employed in amounts of from about 0.2 to about 8 parts, by weight, per 100 parts of hydrophilic monomer. Other monomers that can be present in the polymerization mixture include methoxyethyl methacrylate, acrylic acid, ultra-violet absorbing monomers, and the like and mixtures thereof.

A polymerization catalyst is included in the monomer mixture. The polymerization catalyst can be a compound such as lauroyl peroxide, benzoyl peroxide, isopropyl percarbonate, azobisiso-butyronitrile, and the like and mixtures thereof, that generates free radicals at moderately elevated temperatures, or the polymerization catalyst can be a photoinitiator system such as an aromatic a-hydroxy ketone or a tertiary amine plus a diketone. Illustrative examples of photoinitiator systems are 2-hydroxy-2-methyl-1-phenyl-propan-1-one and a combination of camphorquinone and ethyl 4-(N,N-dimethyl-amino)benzoate. The catalyst is used in the polymerization reaction mixture in catalytically effective amounts, e.g., from about 0.1 to about 2 parts by weight per 100 parts of hydrophilic monomer.

The presently useful WSPCs preferably are included in the contact lenses during polymerization, for example, solution polymerization, to produce the hydrophilic polymeric material. In a particularly useful embodiment, the WSPC in the contact lens is derived from a diluent material used during such polymerization of the hydrophilic polymeric material.

In another broad aspect, the present invention is directed to methods of producing contact lenses. Such methods comprise polymerizing, preferably solution polymerizing at least one hydrophilic monomeric component in the presence of a WSPC to form a contact lens body comprising a hydrophilic polymeric material and the WSPC. The WSPC preferably is included in a diluent used during the polymerizing step. The contact lens body is ready for use in the eye and is advantageously placed in a packaging container, for example, for shipment and/or storage.

The polymerizing step advantageously occurs in a contact lens mold, for example, a conventional contact lens mold. The polymerizing step may take place in a manner substantially similar or analogous to the corresponding step in the conventional wet cast molding process for making hydrophilic contact lenses. The polymerization reaction conditions useful in the present methods are substantially the same as those used in conventional wet cast molding processes for producing hydrophilic contact lenses and, therefore, are not detailed herein.

The resulting contact lens body preferably includes an interpenetrating network or a pseudo interpenetrating network of the hydrophilic polymeric material and the WSPC. One important feature of the present methods is that the WSPC is not replaced, for example, with water, prior to the contact lens being placed into a packaging container or into an eye. As described elsewhere herein, the WSPC in the contact lens in the eye produces one or more benefits.

In a further broad aspect, the present invention is directed to package systems for contact lenses, for example, the present contact lenses. Such package systems comprise a contact lens ready for use in an eye, a liquid medium, preferably an aqueous liquid medium, and a container holding the contact lens and the liquid medium. The contact lens comprises a contact lens body comprising a hydrophilic polymeric material and a WSPC, as described elsewhere herein.

The liquid medium comprises an amount of the WSPC in addition to the WSPC present in the contact lens body. Although the WSPC in the liquid medium need not be the same as the WSPC in the lens body, preferably it is substantially the same WSPC as that present in the lens body. Advantageously, the liquid medium includes the WSPC prior to the liquid medium being placed in contact with the lens body. The presence of the WSPC in the liquid medium preferably is effective to inhibit migration of the WSPC in the lens body from the lens body. Thus, the amount or concentration of the WSPC in the lens body is substantially maintained in the packaging system, and is available for providing one or more benefits, as described elsewhere herein, after the contact lens is placed in an eye. The concentration of the WSPC in the liquid medium may be about equal to, or somewhat more or less than, that present in the lens body prior to the lens body being placed in contact with the liquid medium. The liquid medium, other than the WSPC, may have a composition substantially similar or analogous to liquid medium used in package systems for conventional hydrophilic contact lenses. Saline solutions, buffered saline solutions, other aqueous solutions and the like, together with the WSPC, may be employed.

The container advantageously is sealed, after placing the contact lens and liquid medium in the container, to preserve these components during shipment and storage. The container and seal may be substantially similar or analogous to a conventional blister pack which is used for packaging conventional hydrophilic contact lenses.

Referring now to FIG. 1, a package system in accordance with the present invention is shown at 10. Package system 10 includes a container 12, a contact lens 14, including a contact lens body including a hydrophilic polymeric material and a WSPC, a liquid medium 16, comprising an aqueous saline solution containing a separate amount of the WSPC present in the contact lens, and a removable seal 18.

The container 12 and seal 18 are similar to the container and seal used in a conventional blister pack used with conventional hydrophilic contact lenses.

With the container 12 unsealed, the liquid medium 16 and the contact lens 14, directly from the contact lens mold, are placed therein. The seal 18 is placed over, and secured to the top of container 12, thereby sealing the compartment 20 containing the contact lens 14 in contact with the liquid medium 16.

The contact lens 14 can be used by opening seal 18 (as shown by the shadow lines in FIG. 1), removing lens 14 from compartment 20 and placing the lens into one’s eye. The container 12, liquid medium 16 and seal 18 can then be properly disposed of.

The following non-limiting examples illustrate certain aspects of the present invention:

EXAMPLE 1

A one day disposable, hydrogel-containing contact lens is wet cast molded in a polypropylene mold as follows. A monomer mixture of 98% by weight of 2-hydroxyethyl methacrylate, 1.6% by weight methacrylic acid and 0.4% by weight of ethylene glycol dimethacrylate is formed together with an effective amount of a conventional thermal initiator. This monomer is diluted by 20% by weight with water soluble polyethylene glycol having a molecular weight of about 1000. The diluted solution is added to a polypropylene contact lens mold and is cured using thermal curing. If desired, an ultraviolet light initiator can be included in place of the thermal initiator, and the solution can be cured using ultraviolet light curing. After curing, the lens is removed from the mold and placed in a packaging system similar to a conventional blister pack and hydrated with saline solution. The hydrated lens is formed to have mechanical properties similar to a dry cast molded lens.

EXAMPLE 1A

Alternately, and advantageously, the saline solution used in the package is altered to include about 20% of the polyethylene glycol, which is at substantial equilibrium with both the contact lens and the saline solution in the package. The use of this polyethylene glycol in the saline solution is effective to reduce, or even substantially eliminate, the polyethylene glycol from diffusing out of the contact lens during storage in the package.

EXAMPLE 2

A one day disposable, hydrogel-containing contact lens is wet cast molded in a polypropylene mold as follows. A monomer mixture of 98% by weight of 2-hydroxyethyl methacrylate, 1.6% by weight methacrylic acid and 0.4% by weight of ethylene glycol dimethacrylate is formed together with an effective amount of a conventional thermal initiator. This monomer is diluted by 30% by weight with water soluble polyethylene glycol having a molecular weight of about 1000. The diluted solution is added to a polypropylene contact lens mold and is cured using thermal curing. If desired, an ultraviolet light initiator can be included in place of the thermal initiator, and the solution can be cured using ultraviolet light curing. After curing, the lens is removed from the mold and placed in a packaging system similar to a conventional blister pack and hydrated with saline solution. The hydrated lens is formed to have mechanical properties similar to a dry cast molded lens.

EXAMPLE 2A

Alternately, and advantageously, the saline solution used in the package is altered to include about 30% of the polyethylene glycol, which is at substantial equilibrium with both the contact lens and the saline solution in the package. The use of this polyethylene glycol in the saline solution is effective to reduce, or even substantially eliminate, the polyethylene glycol from diffusing out of the contact lens during storage in the package.

EXAMPLE 3

A one day disposable hydrogel-containing contact lens is wet cast molded in a polypropylene mold as follows. A monomer mixture of 98% by weight of 2-hydroxyethyl methacrylate, 1.6% by weight methacrylic acid and 0.4% by weight of ethylene glycol dimethacrylate is formed together with an effective amount of a conventional thermal initiator. This monomer is diluted by 40% by weight with water soluble polyethylene glycol having a molecular weight of about 1000. The diluted solution is added to a polypropylene contact lens mold and is cured using thermal curing. If desired, an ultraviolet light initiator can be included in place of the thermal initiator, and the solution can be cured using ultraviolet light curing. After curing, the lens is removed from the mold and placed in a packaging system similar to a conventional blister pack and hydrated with saline solution. The hydrated lens is formed to have mechanical properties similar to a dry cast molded lens.

EXAMPLE 3A

Alternately, and advantageously, the saline solution used in the package is altered to include about 40% of the polyethylene glycol, which is at substantial equilibrium with both the contact lens and the saline solution in the package. The use of this polyethylene glycol in the saline solution is effective to reduce, or even substantially eliminate, the polyethylene glycol from diffusing out of the contact lens during storage in the package.

EXAMPLE 4

A one day disposable hydrogel-containing contact lens is wet cast molded in a polypropylene mold as follows. A monomer mixture of 98% by weight of 2-hydroxyethyl methacrylate, 1.6% by weight methacrylic acid and 0.4% by weight of ethylene glycol dimethacrylate is formed together with an effective amount of a conventional thermal initiator. This monomer is diluted by 50% by weight with water soluble polyethylene glycol having a molecular weight of about 1000. The diluted solution is added to a polypropylene contact lens mold and is cured using thermal curing. If desired, an ultraviolet light initiator can be included in place of the thermal initiator, and the solution can be cured using ultraviolet light curing. After curing, the lens is removed from the mold and placed in a packaging system similar to a conventional blister pack and hydrated with saline solution. The hydrated lens is formed to have mechanical properties similar to a dry cast molded lens.

EXAMPLE 4A

Alternately, and advantageously, the saline solution used in the package is altered to include about 50% of the polyethylene glycol, which is at substantial equilibrium with both the contact lens and the saline solution in the package. The use of this polyethylene glycol in the saline solution is effective to reduce, or even substantially eliminate, the polyethylene glycol from diffusing out of the contact lens during storage in the package.

EXAMPLE 5

A one day disposable hydrogel-containing contact lens is wet cast molded in a polypropylene mold as follows. A mixture of 48.8% by weight of 2-hydroxyethyl methacrylate, 0.5% by weight methacrylic acid, 0.7% by weight of a cross-linking component sold under the tradename Craynor 435 and 50% by weight of methyl terminated polyethylene glycol having a molecular weight of about 350 (PEGME-350) is formed together with an effective amount of a conventional thermal initiator. This mixture is added to a polypropylene contact lens mold and is cured using thermal curing. If desired, an ultraviolet light initiator can be included in place of the thermal initiator, and the mixture can be cured using ultraviolet light curing. After curing, the lens is removed from the mold and placed in a packaging system similar to a conventional blister pack and hydrated with saline solution. The hydrated lens is formed to have mechanical properties similar to a dry cast molded lens.

EXAMPLE 5A

Alternately, and advantageously, the saline solution used in the package is altered to include about 50% of the PEGME-350, which is at substantial equilibrium with both the contact lens and the saline solution in the package. The use of this methyl terminated polyethylene glycol in the saline solution is effective to reduce, or even substantially eliminate, the methyl terminated polyethylene glycol from diffusing out of the contact lens during storage in the package.

EXAMPLE 6

A one day disposable hydrogel-containing contact lens is wet cast molded in a polypropylene mold as follows. A mixture of 37.3% by weight of 2-hydroxyethyl methacrylate, 0.6% by weight methacrylic acid, 0.2% by weight of ethylene glycol dimethacrylate, 30.8% by weight of polyethylene glycol having a molecular weight of about 300 and 31.1 by weight of deionized water is formed together with an effective amount of a conventional thermal initiator. The mixture is added to a polypropylene contact lens mold and is cured using thermal curing. If desired, an ultraviolet light initiator can be included in place of the thermal initiator, and the mixture can be cured using ultraviolet light curing. After curing, the lens is removed from the mold and placed in a packaging system similar to a conventional blister pack and hydrated with saline solution. The hydrated lens is formed to have mechanical properties similar to a dry cast molded lens.

EXAMPLE 6A

Alternately, and advantageously, the saline solution used in the package is altered to include about 30.8% of the polyethylene glycol, which is at substantial equilibrium with both the contact lens and the saline solution in the package. The use of this polyethylene glycol in the saline solution is effective to reduce, or even substantially eliminate, the polyethylene glycol from diffusing out of the contact lens during storage in the package.

EXAMPLE 7 TO 18

Each of twelve (12) patients removes a different one of the lenses produced in accordance with Examples 1 to 6 and 1A to 6A from the solution and places it on his/her eye. In each case, while the lens is on the patient’s eye, the polyethylene glycol or methyl terminated polyethylene glycol diffuses out of the lens and into the eye, thereby advantageously increasing the lubrication of the cornea and the eyelid of the eye.

If the patient was to remove the lens, place it into a saline solution and wear it again the next day, the lens would be significantly less comfortable to wear due to the loss of the polyethylene glycol, or methyl terminated polyethylene glycol and the loss of lubrication. In addition, because of the loss of the polyethylene glycol, or methyl terminated polyethylene glycol, the lens has less modulus or strength and appears more “floppy” after the lens is worn in the eye. In effect, the loss of the polyethylene glycol, or methyl terminated polyethylene glycol from the contact lens creates a trigger mechanism and/or provides an indication to the patient to be compliant with the one day disposable modality.

While this invention has been described with respect to various specific examples and embodiments, it is to be understood that the invention is not limited thereto and that it can be variously practiced within the scope of the following claims.

1. A contact lens container for sealing within it a contact lens in a solution, and configured for use with an apparatus including a needle for penetrating the container and introducing through the needle a predetermined substance therein into contact with at least one of the contact lens and solution, and a laser for transmitting radiation onto a penetrated region of the container to thermally reseal the penetrated region and, in turn, seal the contact lens, solution, and predetermined substance within the container, the container comprising: a body defining a chamber; a contact lens and a contact lens solution received within the chamber; a substantially fluid-tight seal formed between the chamber and ambient atmosphere to seal the contact lens and solution within the chamber; a needle penetrable and laser resealable stopper located on the body in fluid communication with the chamber, wherein the stopper is penetrable by the needle to introduce the predetermined substance through the needle and into the chamber, and a penetrated region of the stopper is thermally resealable by application of radiation from the laser thereto to reseal the stopper and, in turn, seal the contact lens, solution and predetermined substance within the chamber.

2. A contact lens container as defined in claim 1, further comprising the predetermined substance.

3. A contact lens container as defined in claim 1, wherein the needle penetrable and laser resealable stopper includes an inner layer in fluid communication with the chamber that is compatible with the contact lens, solution and the predetermined substance, and an outer layer that is needle penetrable and laser resealable.

4. A contact lens container as defined in claim 3, wherein the inner layer does not leach more than a predetermined amount of leachables into at least one of the contact lens, solution and predetermined substance.

5. A contact lens container as defined in claim 2, wherein the body includes a base surface forming a base portion of the chamber, the base surface defines at least one substantially convex portion that supports a substantially concave surface of the contact lens thereon and defines an interface therebetween, and the interface is in fluid communication with the stopper for receiving the predetermined substance therein.

6. A contact lens container as defined in claim 5, wherein the interface contains a greater concentration of the predetermined substance than the other portions of the chamber.

7. A contact lens container as defined in claim 6, wherein the concave side of the contact lens defining the interface includes a greater concentration of the predetermined substance than does the opposing convex side of the contact lens.

8. A contact lens container as defined in claim 5, wherein the base surface defines a plurality of relatively raised surface areas and relatively recessed surfaces areas between relatively raised surface areas, and the relatively recessed surface areas are in fluid communication with the stopper for receiving predetermined substance therein.

9. A contact lens container as defined in claim 8, wherein the relatively recessed surface areas are defined by substantially radially extending recesses, and the body further defines a fluid passageway in fluid communication between the recesses and the stopper for introducing the predetermined substance therethrough and into the recesses.

10. A contact lens container as defined in claim 2, wherein the predetermined substance is selected from the group consisting of a preservative; a chelating agent; an anionic component; a cationic component; a zwitterionic component; an acid; a base; an alcohol; a glycol; a polymeric agent; a reducing agent; a salt; a surfactant; an antioxidant; a cleaning agent; a disinfecting agent; a wetting agent; a hydrating agent; a coloring agent; an ultraviolet absorbing agent; a gas; a lipid; an oil; a phospholipid; a lubricant; a buffering agent; a mineral; a nutrient; a vitamin; a biological macromolecule; a small molecule; an antibiotic; a biopolymer; a protein; and a nucleic acid.

11. A contact lens container as defined in claim 1, wherein the stopper includes a thermoplastic elastomer that is heat resealable to hermetically seal the penetrated region by applying laser radiation at a predetermined wavelength and power thereto, and defines (i) a predetermined wall thickness, (ii) a predetermined color and opacity that substantially absorbs the laser radiation at the predetermined wavelength and substantially prevents the passage of the radiation through the predetermined wall thickness thereof, and (iii) a predetermined color and opacity that causes the laser radiation at the predetermined wavelength and power to hermetically seal the penetrated region in a predetermined time period of less than or equal to about 5 seconds and substantially without burning the stopper.

12. A contact lens container as defined in claim 1, wherein the stopper includes a thermoplastic elastomer that is heat resealable to hermetically seal the needle aperture by applying laser radiation at a predetermined wavelength and power thereto, and includes (i) a styrene block copolymer; (ii) an olefin; (iii) a predetermined amount of pigment that allows the second material portion to substantially absorb laser radiation at the predetermined wavelength and substantially prevent the passage of radiation through the predetermined wall thickness thereof, and hermetically seal the needle aperture formed in the needle penetration region thereof in a predetermined time period of less than or equal to about 5 seconds; and (iv) a predetermined amount of lubricant that reduces friction forces at an interface of the needle and stopper during needle penetration thereof.

13. A contact lens container as defined in claim 1, wherein the stopper includes a thermoplastic elastomer that is heat resealable to hermetically seal the penetrated region thereof by applying laser radiation at a predetermined wavelength and power thereto, and includes (i) a first polymeric material in an amount within the range of about 80% to about 97% by weight and defining a first elongation; (ii) a second polymeric material in an amount within the range of about 3% to about 20% by weight and defining a second elongation that is less than the first elongation of the first polymeric material; (iii) a pigment in an mount that allows the second material portion to substantially absorb laser radiation at the predetermined wavelength and substantially prevent the passage of radiation through the predetermined wall thickness thereof, and hermetically seal the penetrated region in a predetermined time period of less than or equal to about 5 seconds; and (iv) a lubricant in an amount that reduces friction forces at an interface of the needle and stopper during needle penetration thereof.

14. An assembly comprising a contact lens container as defined in claim 1; a filling apparatus comprising a needle manifold including a plurality of needles spaced relative to each other and movable relative to a container support for penetrating a plurality of containers mounted on the support within the filling apparatus, introducing the predetermined substance into the containers through the needles, and withdrawing the needles from the filled containers; and a plurality of laser optic assemblies, wherein each laser optic assembly is connectable to a source of laser radiation, and is focused substantially on a penetration spot of the respective stopper for applying laser radiation thereto and resealing the respective penetrated region.

15. A contact lens container for sealing within it a contact lens in a solution, and configured for use with an apparatus including a needle for penetrating the container and introducing through the needle a predetermined substance therein into contact with at least one of the contact lens and solution, and a laser for transmitting radiation onto a penetrated region of the container to thermally reseal the penetrated region and, in turn, seal the contact lens, solution, and predetermined substance within the container, the container comprising: first means for forming a chamber; a contact lens and a contact lens solution received within the chamber; a substantially fluid-tight seal between the chamber and ambient atmosphere to seal the contact lens and solution within the chamber; second means in fluid communication with the chamber for penetration by the needle to introduce the predetermined substance through the needle and into the chamber, and for thermal resealing by application of radiation from the laser thereto to reseal the second means and, in turn, seal the contact lens, solution and predetermined substance within the chamber.

16. A contact lens container as defined in claim 15, wherein the first means is a body, and the second means is a needle penetrable and laser resealable stopper in fluid communication with the chamber that is penetrable by the needle to introduce the predetermined substance through the needle and into the chamber and is thermally resealable by application of radiation from the laser thereto to reseal a penetrated region of the stopper and, in turn, seal the contact lens, solution and predetermined substance within the chamber.

17. A method of providing a contact lens container containing therein a contact lens and a solution, and adding thereto a predetermined substance, the method comprising the following steps: providing a contact lens container including a body defining a contact lens storage chamber, and a needle penetrable and laser resealable stopper in fluid communication with the chamber; introducing the contact lens and solution into the chamber, and sealing the contact lens and solution within the chamber relative to the ambient atmosphere; inserting a needle through the stopper and into fluid communication with the chamber; introducing the predetermined substance through the needle and into the chamber; withdrawing the needle from the stopper; and applying laser radiation to a penetrated region of the stopper, thermally resealing the penetrated region of the stopper and, in turn, sealing the contact lens, solution and predetermined substance within the chamber.

18. A method as defined in claim 17, further comprising the step of terminally sterilizing the contact lens container with the contact lens and solution sealed therein prior to introducing the predetermined substance into the container.

19. A method as defined in claim 18, further comprising the step of introducing the predetermined substance into an interface formed between a substantially concave surface of the contact lens and a wall of the chamber, and at least one of (i) impregnating at least a portion of the predetermined substance into the concave surface of the contact lens, and (ii) depositing at least a portion of the predetermined substance onto the concave surface of the contact lens.

20. A method as defined in claim 19, further comprising the step of applying a greater amount of the predetermined substance to the concave side of the contact lens in comparison to the opposing convex side of the contact lens.

21. A method as defined in claim 20, further comprising the step of applying the concave side of the contact lens into contact with a user’s cornea such that a greater amount of the predetermined substance is located within the interface between the concave side of the contact lens and the eye in comparison to the opposite convex side of the contact lens.
Contact Lens Description
FIELD OF THE INVENTION

The present invention relates to a contact lens storage container, also known as a blister package, having a needle penetrable and thermally resealable stopper for aseptically introducing a substance into the contact lens storage container through the stopper and thermally resealing the resulting penetration hole in the stopper, and to apparatus and methods for filling such a container.

BACKGROUND OF THE INVENTION

Referring to FIG. 1, a prior art blister package 10 includes a cavity 12 that receives a contact lens solution or “packing” solution and a contact lens within the solution. The cavity 12 is covered with a sealing flat covering layer (not shown) that is detachably sealed to a flange 14 that surrounds the cavity 12. The flange 14 of the blister package 10 defines gripping areas 16 that allow a user to grip the package and unseal the covering layer to access the contact lens stored within the cavity 12. The packing solution may have any of a variety of components, additives or other substances added thereto, such as physiologically compatible surfactants, cleaning agents, wetting agents, etc., as shown, for example, in U.S. Pat. No. 5,882,687. When manufacturing some such blister packages, the contact lens is placed within the cavity 12 together with the packing solution and any components, additives or other substances added thereto, and then the covering layer is sealed to the flange 14 to seal the contact lens, solution and any additives, etc. therein. The sealed package is then terminally sterilized, such as by the application of heat or gamma radiation thereto.

One of the drawbacks associated with such prior art blister packages and apparatus and methods for filling such packages is that the additives or other substances are introduced into the package prior to terminal sterilization. As a result, additives or other substances that can be damaged by terminal sterilization cannot be used. In other situations, terminal sterilization can negatively affect the additives or other substances and/or the solution or contact lens packaged with such additives or other substances.

Another drawback associated with prior art contact lens storage containers, and apparatus and methods for introducing additives, such as medicaments, to the containers, and/or to an eye after application of a contact lens to the eye, is that a substantial portion of the medicament or other additive is located on the external or convex surface of the contact lens. When the user blinks, the fluid within the eye, such as the tear film, can relatively rapidly flush away any such medicament or other additive located on the external or convex surface of the contact lens. The flushed medicament or other additive can flow into the lacryomo nasal duct (also referred to as the lachrymal nasal duct, i.e., a duct running between the base of the eye and the nasal passageway) which can, in turn, lead to systemic absorption of the flushed additive or other substance and, in some cases, give rise to systemic side effects.

Accordingly, it is an object of the present invention to overcome one or more of the above-described drawbacks and disadvantages of the prior art.

SUMMARY OF THE INVENTION

In accordance with a first aspect, the present invention is directed to a contact lens container for sealing within it a contact lens in a solution. The contact lens container is configured for use with an apparatus including a needle for penetrating the container and introducing through the needle a predetermined substance therein into contact with the contact lens and/or solution. A laser of the apparatus transmits radiation onto a penetrated region of the container to thermally reseal the penetrated region and, in turn, seal the contact lens, solution, and predetermined substance within the container. The container comprises a body defining a chamber; a contact lens and a contact lens solution received within the chamber; and a substantially fluid-tight seal formed between the chamber and ambient atmosphere to seal the contact lens and solution within the chamber. A needle penetrable and laser resealable stopper is located on the body in fluid communication with the chamber. The stopper is penetrable by the needle to introduce the predetermined substance through the needle and into the chamber, and a penetrated region of the stopper is thermally resealable by application of radiation from the laser thereto to reseal the stopper and, in turn, seal the contact lens, solution and predetermined substance within the chamber.

In one embodiment of the present invention, the needle penetrable and laser resealable stopper includes an inner layer in fluid communication with the chamber that is compatible with the contact lens, solution and the predetermined substance, and an outer layer that is needle penetrable and laser resealable. In one such embodiment, the inner layer does not leach more than a predetermined amount of leachables into the contact lens, solution and/or predetermined substance.

In one embodiment of the present invention, the body includes a base surface forming a base portion of the chamber. The base surface defines at least one substantially convex portion that supports a substantially concave surface of the contact lens thereon, and defines an interface therebetween. The interface is in fluid communication with the stopper for receiving the predetermined substance therein. Preferably, the interface contains a greater concentration of the predetermined substance than do the other portions of the chamber. In one such embodiment, the concave side of the contact lens defining the interface includes a greater concentration of the predetermined substance than does the opposing convex side of the contact lens. In one such embodiment, the base surface defines a plurality of relatively raised surface areas and relatively recessed surfaces areas between relatively raised surface areas. The relatively recessed surface areas are in fluid communication with the stopper for receiving predetermined substance therein. In one such embodiment, the relatively recessed surface areas are defined by substantially radially extending recesses, and the body further defines a fluid passageway in fluid communication between the recesses and the stopper for introducing the predetermined substance therethrough and into the recesses.

In one embodiment of the present invention, the predetermined substance is selected from the group including a preservative; a chelating agent; an anionic component; a cationic component; a zwitterionic component; an acid; a base; an alcohol; a glycol; a polymeric agent; a reducing agent; a salt; a surfactant; an antioxidant; a cleaning agent; a disinfecting agent; a wetting agent; a hydrating agent; a coloring agent; an ultraviolet absorbing agent; a gas; a lipid; an oil; a phospholipid; a lubricant; a buffering agent; a mineral; a nutrient; a vitamin; a biological macromolecule; a small molecule; an antibiotic; a biopolymer; a protein; and a nucleic acid.

In one embodiment of the present invention, the stopper includes a thermoplastic elastomer that is heat resealable to hermetically seal the penetrated region by applying laser radiation at a predetermined wavelength and power thereto, and defines (i) a predetermined wall thickness, (ii) a predetermined color and opacity that substantially absorbs the laser radiation at the predetermined wavelength and substantially prevents the passage of the radiation through the predetermined wall thickness thereof, and (iii) a predetermined color and opacity that causes the laser radiation at the predetermined wavelength and power to hermetically seal the penetrated region in a predetermined time period of less than or equal to about 5 seconds and substantially without burning the stopper.

In one embodiment of the present invention, the stopper includes a thermoplastic elastomer that is heat resealable to hermetically seal the needle aperture by applying laser radiation at a predetermined wavelength and power thereto, and includes (i) a styrene block copolymer; (ii) an olefin; (iii) a predetermined amount of pigment that allows the second material portion to substantially absorb laser radiation at the predetermined wavelength and substantially prevent the passage of radiation through the predetermined wall thickness thereof, and hermetically seal the needle aperture formed in the needle penetration region thereof in a predetermined time period of less than or equal to about 5 seconds; and (iv) a predetermined amount of lubricant that reduces friction forces at an interface of the needle and stopper during needle penetration thereof.

In one embodiment of the present invention, the stopper includes a thermoplastic elastomer that is heat resealable to hermetically seal the penetrated region thereof by applying laser radiation at a predetermined wavelength and power thereto, and includes (i) a first polymeric material in an amount within the range of about 80% to about 97% by weight and defining a first elongation; (ii) a second polymeric material in an amount within the range of about 3% to about 20% by weight and defining a second elongation that is less than the first elongation of the first polymeric material; (iii) a pigment in an mount that allows the second material portion to substantially absorb laser radiation at the predetermined wavelength and substantially prevent the passage of radiation through the predetermined wall thickness thereof, and hermetically seal the penetrated region in a predetermined time period of less than or equal to about 5 seconds; and (iv) a lubricant in an amount that reduces friction forces at an interface of the needle and stopper during needle penetration thereof.

In accordance with another aspect of the present invention, the contact lens container is part of an assembly including a filling apparatus comprising a needle manifold including a plurality of needles spaced relative to each other and movable relative to a container support for penetrating a plurality of containers mounted on the support within the filling apparatus, introducing the predetermined substance into the containers through the needles, and withdrawing the needles from the filled containers. The filling apparatus further includes a plurality of laser optic assemblies, wherein each laser optic assembly is connectable to a source of laser radiation, and is focused substantially on a penetration spot of a respective stopper for applying laser radiation thereto and resealing the respective penetrated region.

In accordance with another aspect, the present invention is directed to a contact lens container for sealing within it a contact lens in a solution. The container is configured for use with an apparatus including a needle for penetrating the container and introducing through the needle a predetermined substance therein into contact with the contact lens and/or solution. A laser of the apparatus transmits radiation onto a penetrated region of the container to thermally reseal the penetrated region and, in turn, seal the contact lens, solution, and predetermined substance within the container. The container comprises first means for forming a chamber; a contact lens and a contact lens solution received within the chamber; a substantially fluid-tight seal between the chamber and ambient atmosphere to seal the contact lens and solution within the chamber; and second means in fluid communication with the chamber for penetration by the needle to introduce the predetermined substance through the needle and into the chamber, and for thermal resealing by application of radiation from the laser thereto to reseal the second means and, in turn, seal the contact lens, solution and predetermined substance within the chamber.

In a currently preferred embodiment of the present invention, the first means is a body, and the second means is a needle penetrable and laser resealable stopper in fluid communication with the chamber that is penetrable by the needle to introduce the predetermined substance through the needle and into the chamber, and is thermally resealable by application of radiation from the laser thereto to reseal a penetrated region of the stopper and, in turn, seal the contact lens, solution and predetermined substance within the chamber.

In accordance with another aspect, the present invention is directed to a method of providing a contact lens container containing therein a contact lens and a solution, and adding thereto a predetermined substance. The method comprises the following steps: (a) providing a contact lens container including a body defining a contact lens storage chamber, and a needle penetrable and laser resealable stopper in fluid communication with the chamber; (b) introducing the contact lens and solution into the chamber, and sealing the contact lens and solution within the chamber relative to the ambient atmosphere; (c) inserting a needle through the stopper and into fluid communication with the chamber; (d) introducing the predetermined substance through the needle and into the chamber; (e) withdrawing the needle from the stopper; and (f) applying laser radiation to a penetrated region of the stopper, thermally resealing the penetrated region of the stopper and, in turn, sealing the contact lens, solution and predetermined substance within the chamber.

The method preferably further comprises the step of terminally sterilizing the contact lens container with the contact lens and solution sealed therein prior to introducing the predetermined substance into the container.

In one embodiment the method further comprises the step of introducing the predetermined substance into an interface formed between a substantially concave surface of the contact lens and a wall of the chamber, and (i) impregnating at least a portion of the predetermined substance into the concave surface of the contact lens, and/or (ii) depositing at least a portion of the predetermined substance onto the concave surface of the contact lens. In one such embodiment, the method further comprises the step of applying a greater amount of the predetermined substance to the concave side of the contact lens in comparison to the opposing convex side of the contact lens.

Also in one such embodiment, the method further comprises the step of applying the concave side of the contact lens into contact with a user’s cornea such that a greater amount of the predetermined substance is located within the interface between the concave side of the contact lens and the eye in comparison to the opposite convex side of the contact lens.

One advantage of the present invention is that the predetermined substance can be aseptically introduced and sealed within the container after terminally sterilizing the contact lens and solution within the container, thus avoiding the problems encountered in the prior art in connection with introducing such predetermined substances into the container prior to terminal sterilization as described above. Yet another advantage of certain embodiments of the present invention is that a greater concentration of a predetermined substance can be introduced into and/or on the concave side of the contact lens, thus enabling a greater concentration of the substance to be sandwiched between the contact lens and the user’s eye, and thereby allowing a relatively sustained release of the substance into the eye and substantially preventing the systemic absorption of the substance and negative side effects encountered in the prior art.

Other advantages of the present invention and/or of the currently preferred embodiments thereof will become more readily apparent in view of the following detailed description of the currently preferred embodiments and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a prior art blister package for storing a contact lens.

FIG. 2 is a top perspective view of a contact lens storage container according to an exemplary embodiment of the invention.

FIG. 3 is a bottom perspective view of the contact lens storage container of FIG. 2.

FIG. 4 is a bottom perspective view of the contact lens storage container of FIG. 2 showing a filling needle inserted into a resealable stopper of the container for introducing an additive or other substance into the container after terminal sterilization of the contact lens and packing solution therein.

FIG. 5 is a perspective cross-sectional view of the contact lens storage container and filling needle of FIG. 4.

FIG. 6 is a somewhat schematic cross-sectional view of the contact lens storage container and filling needle of FIG. 4 showing the flow of additive and/or other substance from the filling needle, through the resealable stopper, and into the interface between the concave side of the contact lens and the base wall of the storage cavity of the container.

FIG. 7 is a top perspective view of a second embodiment of a contact lens storage container according to an exemplary embodiment of the invention.

FIG. 8 is an exploded side elevational view of the contact lens storage container of FIG. 7.

FIG. 9 is another side elevational view of the contact lens storage container of FIG. 7 showing the filling needle adjacent to the resealable stopper.

FIG. 10 is a top perspective view of a third embodiment of a contact lens storage container according to an exemplary embodiment of the invention.

FIG. 11 is a schematic illustration of an exemplary embodiment of an apparatus of the present invention for molding, assembling, needle filling and laser resealing contact lens storage containers.

FIG. 12 is a perspective view of a first exemplary embodiment of a filling needle used in the apparatus of FIG. 11 for needle filling the contact lens storage containers.

FIG. 13 is a cross-sectional view of a tip portion of the needle of FIG. 12.

FIG. 14 is a perspective view of a second exemplary embodiment of a filling needle used in the apparatus of FIG. 11 for needle filling the contact lens storage containers.

FIG. 15 is a cross-sectional view of a tip portion of the needle of FIG. 14.

FIG. 16 is a perspective view of a second exemplary embodiment of a filling needle used in the apparatus of FIG. 11 for needle filling the contact lens storage containers.

FIG. 17 is a cross-sectional view of a tip portion of the needle of FIG. 16.

DETAILED DESCRIPTION OF THE CURRENTLY PREFERRED EMBODIMENTS

Referring to FIGS. 2-6, a contact lens storage container, also known as a blister package (referred to herein as a “contact lens storage container” or “container”) is indicated generally by the reference numeral 20. The container 20 includes a body 21 defining a contact lens storage recess or cavity 22. In the illustrated embodiment, the base of the cavity 22 is defined by a substantially dome-shaped wall 24. The dome-shaped base 24 defines a plurality of radially extending recesses or slits 26 that are angularly spaced relative to each other, and a central recessed portion 28 in fluid communication with the radially extending recesses 26. As shown typically in FIG. 2, the base 24 defines a plurality of inner surface portions 30 extending between the radially extending recesses 26 and together forming a substantially dome-shaped or convex surface for supporting thereon a contact lens (not shown) received within the storage cavity 22. As shown typically in FIG. 3, the base 24 further defines on outer surface 32 located on an opposite side of the base wall relative to the inner surface 30.

The body 21 further defines a substantially planar flange 31 extending about the periphery of the storage cavity 22, and a plurality of tabs 33 extending downwardly from the end portions of the flange on opposite sides of the body relative to each other. One or more of the tabs 33 and/or the flange 31 define gripping areas that allow a user to grip the body to hold the container. The flange 31 of the body 21 defines a substantially circular raised sealing surface 35 that is located on the upper surface of the flange 31 and extends about the periphery of the storage cavity 22. As shown typically in FIG. 6, the container 20 further includes a removable sealing cover 37 that is sealed to the sealing surface 35 after loading the storage cavity 22 with a contact lens and packing solution to form a fluid tight or hermetic seal between the interior and exterior of the storage cavity. In one embodiment, the sealing cover 37 is a laminated foil cover, and an adhesive is used to releasably secure and seal the foil cover to the sealing surface 35 and/or flange 31, wherein both the foil cover and adhesive are of types known to those of ordinary skill in the pertinent art. As may be recognized by those of ordinary skill in the pertinent art based on the teachings herein, the body 21, cover 37, and mechanism for releasably sealing the cover to the body may take any of numerous different types or configurations that are currently known, or that later become known.

As shown in FIGS. 3-6, the body 21 further defines a filling boss 34 extending outwardly from a central region of the outer surface 32 of the base wall 24. As shown in FIG. 5, the filling boss 34 defines an internal stopper recess 36 formed in the end portion of the boss, and a fluid conduit or channel 38 extending through the boss and in fluid communication with the central region 28 and radially-extending recesses 26 of the base 24 and thus in fluid communication with the storage cavity 22. A resealable stopper 40 is received within the stopper recess 36 of the filling boss 34. As indicated further below, the stopper 40 and filling boss 34 may be formed in any of numerous different ways, out of any of numerous different materials, and may take any of numerous different configurations, that are currently known, or that later become known. For example, the stopper 40 can be inserted into the boss and fixedly secured thereto, such as by a locking ring or other locking member, or by an adhesive, or the stopper may be co-molded with the body, such as by over-molding the stopper to the body.

As shown typically in FIGS. 4-6, the resealable stopper 40 is penetrable by a hypodermic or other type of filling needle or injection member 50 that is inserted through the resealable stopper 40 such that the tip of the needle is received within the fluid channel 38 in order to dispense a substance, such as a medicament, into the cavity 22 and thus into the packing solution and/or into contact with the contact lens stored therein. In the illustrated embodiment, the fluid channel 38 is sized to allow for enough space for the bevel and filling aperture(s) of the filling needle to enter the channel and introduce the substance therein. As shown typically in FIG. 6, when the substance is injected through the needle 50 and into the channel 38, the substance flows through the central region 28 of the base wall 24, and into the radially-extending recesses 26. As a result, as shown typically in FIG. 6, the substance is deposited into the interface between the contact lens and the base wall. Once the desired amount of substance is introduced into the container 20, the needle 50 is withdrawn from the stopper 40, a heat or other energy source is applied to at least the portion of the resealable stopper 40 punctured by the needle 50 to, in turn, seal the punctured portion and hermetically seal the substance within the container. Thus, the substance may be added to the container 20 after the contact lens and packing solution and/or other components are sealed within the container and terminally sterilized.

One advantage of the illustrated embodiment of the invention is that a significantly greater amount of the substance can be introduced into the interface between the contact lens and the base wall 24 to thereby provide a greater concentration of the substance on the concave or inner side of the contact lens in comparison to the convex or outer side of the contact lens. Accordingly, when the contact lens is removed from the container 20 and applied to an eye, the portion of the contact lens containing the greater concentration of substance is placed into direct contact with cornea of the eye. The cornea can be a relatively slow absorbing region of the eye as compared to other regions of the eye, and thus the residence time of the substance on the eye for the substance located on the concave surface of the contact lens can be significantly greater than the residence time of any substance located on the convex side of the lens and therefore a relatively sustained release of the substance into the eye can be achieved. In addition, the draining of substantial amounts of the substance into the nasal ducts and the associated systemic absorption of such substances as encountered in the prior art can be substantially avoided.

However, as may be recognized by those of ordinary skill in the pertinent art based on the teachings herein, the substance be introduced into all regions of the storage cavity, can be introduced into selective regions of the storage cavity, can be substantially uniformly applied to all surfaces of the contact lens, can be applied to substantially only select surfaces of the contact lens, and/or can be selectively applied in different concentrations to different surfaces or different surface regions of the contact lens. For example, if the surface of the lens that is concave when located in an eye is normally convex when located in the storage container, a greater concentration of the substance can be applied to the convex surface of the lens when located in the storage container.

After injecting the container 20 with the substance and withdrawing the needle 50 from the stopper 40, the penetrated region of the stopper defines a needle hole along the path of the withdrawn needle. Upon withdrawing the needle, the material of the resealable stopper may be sufficiently resilient to close upon itself in the penetrated region and thereby maintain the container in a sealed condition. However, as described above, vapors, gases and/or liquid may be allowed over time to pass through the needle hole, and therefore container is passed through a sealing station, as shown and described below with reference to FIG. 11, to reseal the resulting needle hole in the stopper 40 after withdrawing the needle therefrom. When the 40 is heated by a laser or other such thermal or radiation source, and maintained at a sufficient temperature, the material of the resealable stopper fuses and reseals the needle hole. As a result, the needle hole is eliminated from the exterior region of the resealable stopper to thereby maintain a hermetic seal between the interior and exterior of the storage cavity.

Referring to FIGS. 7-9, another exemplary embodiment of a contact lens storage container of the invention is indicated generally by the reference numeral 120. The contact lens storage container 120 is substantially similar to the container 20 described above with reference to FIGS. 2-6, and therefore like reference numerals preceded by the number “1″ are used to indicate like elements. A primary difference of the container 120 in comparison to the container 20 above is that the filling boss 134 and stopper 40 are spaced laterally relative to the storage cavity 122, and the fluid channel 138 extends laterally between the inner surface of the stopper 140 and the storage cavity 122. Also in this embodiment, the interior surface 130 of the base wall 124 of the storage cavity 122 defines a substantially smooth concave shape as in certain prior art contact lens storage containers. When the substance is introduced through a needle (not shown) that penetrates the stopper, the substance flows through the channel 138 and into the cavity 122. Because the base wall 130 of the cavity is substantially convex, the substance flows into contact with the concave side of the contact lens. Accordingly, this embodiment can facilitate forming a greater concentration of the substance on the inner or concave side of the contact lens that contacts the eye as opposed to the outer or convex side of the contact lens. Another advantage of this embodiment is that the tooling used to mold and/or assemble prior art containers can be modified to form the containers of the invention.

Referring to FIG. 10, another exemplary embodiment of a contact lens storage container of the invention is indicated generally by the reference numeral 220. The contact lens storage container 220 is substantially similar to the containers 20 and 120 described above, and therefore like reference numerals preceded by the number “2″, or preceded by the numeral “2″ instead of the numeral “1″, are used to indicate like elements. A primary difference of the container 220 is that the stopper 240 is located at an edge 238 of the container. The channel 236 connects the stopper 40 in fluid communication with the cavity 222. When the substance is introduced through a needle (not shown) that penetrates the stopper, the substance flows through the channel 238 and into the cavity 222. Because the base wall 230 of the cavity is substantially convex, the substance flows into contact with the concave side of the contact lens. Accordingly, this embodiment can facilitate forming a greater concentration of the substance on the inner or concave side of the contact lens that contacts the eye as opposed to the outer or convex side of the contact lens.

The substance that is injected through the stopper 40 can be an active pharmaceutical ingredient, such as any of the following non-limiting examples: a preservative; a chelating agent, for example, EDTA; an anionic component; a cationic component; a zwitterionic component; an acid; a base; an alcohol; a glycol; a polymeric agent; a reducing agent; a salt, comprised of, for example sodium, calcium, magnesium, phosphate or chloride; a surfactant; an antioxidant; a cleaning agent; a disinfecting agent; a wetting agent; a hydrating agent; a coloring agent; an ultraviolet absorbing agent; a gas, for example, nitrogen, oxygen, or carbon dioxide; a lipid; an oil; a phospholipid; a lubricant; a buffering agent; a mineral; a nutrient; a vitamin; or a drug, for example, a biological macromolecule, a small molecule, or an antibiotic; or a biopolymer, such as a peptide, a protein, for example an enzyme, or a nucleic acid. As may be recognized by those of ordinary skill in the pertinent art based on the teachings herein, the substance also may be any of numerous different pharmaceutical ingredients or other substances that are currently known, or that later become known, that can be deposited onto and/or absorbed into one or more surfaces of a contact lens, or that can be introduced into the packing solution for the contact lens. In addition, the packing solution may take any the form of any of numerous different contact lens solutions that are currently known or that later become known, including with limitation saline solutions and/or cleaning solutions.

If desired, and with reference to FIG. 11, the stopper 40 can be co-molded with body 21, such as by over-molding the stopper to the body in a molding machine 68. Alternatively, the stopper 40 may be molded in the same mold as the container body 21, and at least one of the stopper and the body may be assembled within or adjacent to the mold in accordance with the teachings of commonly-assigned U.S. patent application Ser. Nos. 11/074,454 and 11/074,513 incorporated by reference below, and U.S. Provisional Patent Application Ser. No. 60/727,899 filed Oct. 17, 2005, entitled “Sterile De-Molding Apparatus And Method”, which is hereby expressly incorporated by reference as part of the present disclosure. However, as may be recognized by those of ordinary skill in the pertinent art, the stopper and body can be molded and assembled in any of numerous different ways that are currently known, or that later become known. As also shown in FIG. 11, the assembled stoppers and container bodies are fed into a transfer station 70. Preferably, the laminar flow source 72 directs a substantially laminar flow 74 of sterile air or other gases over the assembled stopper and container bodies during molding, transfer and contact lens assembly.

The transfer station 70 may include any of numerous different types of container conveying systems that are currently known or that later become known for performing the function of transporting the assembled containers 20 therethrough. For example, the conveying system may include a vibratory feed table or tray or other input device for receiving the assembled containers 20 into the transfer station 70, and one or more conveying systems operatively coupled to the input device for transporting the containers therefrom in a single file or other desired configuration. For example, the conveying system may include a vibratory feed system, a closed loop conveyor, or a rotatably driven lead screw. As may be recognized by those or ordinary skill in the pertinent art based on the teachings herein, the conveying system may take the form of any of numerous different conveying systems that are currently known or that later become known.

The contact lens and hydrating solution are added to the container 20 at a contact lens assembly station 76. In addition, the container 20 is sealed with a foil or other cover 37 (FIG. 6), as is known in the art. While these steps have been shown as occurring at one step within the contact lens assembly station, it is understood that these steps may also occur separately, at separate stations. The container 20 is then terminally sterilized, such as by exposing the assembly to heat, beta and/or gamma radiation in a manner known to those of ordinary skill in the pertinent art. After sterilizing, the exposed end of the stopper 42 may be covered with a cap and/or sealing member so that the exposed end of the stopper 42 remains sterile when the container 20 is moved from one location to another. As may be recognized by those of ordinary skill in the pertinent art based on the teachings herein, the containers can be terminally sterilized in any of numerous different ways that are currently known, or that later become known.

Each container 20 including the contact lens and solution aseptically sealed within the container, is then needle filled with a predetermined substance through the stopper 40 and the resulting needle hole in the stopper is thermally resealed in accordance with the teachings of any of the following patent applications and patents that are hereby incorporated by reference in their entireties as part of the present disclosure: U.S. patent application Ser. No. 10/766,172 filed Jan. 28, 2004, entitled “Medicament Vial Having A Heat-Sealable Cap, And Apparatus and Method For Filling The Vial”, which is a continuation-in-part of similarly titled U.S. patent application Ser. No. 10/694,364, filed Oct. 27, 2003, which is a continuation of similarly titled co-pending U.S. patent application Ser. No. 10/393,966, filed Mar. 21, 2003, which is a divisional of similarly titled U.S. patent application Ser. No. 09/781,846, filed Feb. 12, 2001, now U.S. Pat. No. 6,604,561, issued Aug. 12, 2003, which, in turn, claims the benefit of similarly titled U.S. Provisional Application Ser. No. 60/182,139, filed Feb. 11, 2000; similarly titled U.S. Provisional Patent Application No. 60/443,526, filed Jan. 28, 2003; similarly titled U.S. Provisional Patent Application No. 60/484,204, filed Jun. 30, 2003; U.S. patent application Ser. No. 10/655,455, filed Sep. 3, 2003, entitled “Sealed Containers And Methods Of Making And Filling Same”; U.S. patent application Ser. No. 10/983,178 filed Nov. 5, 2004, entitled “Adjustable Needle Filling and Laser Sealing Apparatus and Method; U.S. patent application Ser. No. 11/070,440 filed Mar. 2, 2005, entitled “Apparatus and Method for Needle Filling and Laser Resealing”; U.S. patent application Ser. No. 11/074,513 filed Mar. 7, 2005, entitled “Apparatus for Molding and Assembling Containers with Stoppers and Filling Same; and U.S. patent application Ser. No. 11/074,454 filed Mar. 7, 2005, entitled “Method for Molding and Assembling Containers with Stoppers and Filling Same”.

In accordance with such teachings, the needle filling and laser resealing station 78 comprises a needle manifold including a plurality of needles 50 spaced relative to each other and movable relative to a conveyor holding the containers 20 for penetrating a plurality of containers 20 mounted on the portion of the conveyor within the filling station, introducing the predetermined substance into the containers through the needles, and withdrawing the needles from the filled containers. The laser resealing station comprises a plurality of laser optic assemblies, and each laser optic assembly is located over a respective container position of the conveyor located within the respective laser resealing station. Each laser optic assembly is connectable to a source of laser radiation, and is focused substantially on a penetration spot on the stopper of the respective container 20 for applying laser radiation thereto and resealing the respective needle aperture. The laser resealing station may preferably further comprise a plurality of optical sensors. Each optical sensor is mounted adjacent to a respective laser optic assembly and is focused substantially on the laser resealed region of a stopper of the respective laser optic assembly, and generates signals indicative of the temperature of the laser resealed region to thereby test the integrity of the thermal seal.

As disclosed above, the needle 50 is used to inject a substance into the container 20. In particular, referring to FIGS. 12 and 13, a first embodiment of a needle 50 has a pointed, non-coring tip 52 in which an angle a of the tip 52 relative to the body of the needle 50 in cross-section is within the range of about 25.degree. to about 35.degree., preferably about 28.degree. to about 32.degree., and most preferably about 30.degree.. The smooth, sharply-pointed, gradually increasing angle of the needle tip allows for a relatively smooth, and gradual expansion of the needle hole upon penetrating the stopper. Further, the memory of the preferred thermoplastic blends of the stopper causes the needle hole to substantially close on itself upon withdrawing the needle therefrom, thus reducing the requisite area of impingement by the laser beam for resealing, and reducing cycle time. In addition, this further reduces the possibility of contaminating the interior of the container between needle filling and laser resealing. If desired, the stopper surface may be Teflon coated or otherwise coated with a low-friction material to further reduce friction, and thus the formation of particles, at the needle/stopper interface.

The needle tip further defines axially oblong flow aperture 54 on a side of the needle 50. The aperture 54 is located approximately a distance “d” from an end of the tip 52 of the needle 50. The distance “d” can range from about 0.01 inch to about 0.05 inch and in an exemplary embodiment is about 0.038 inch. The fluid in the needle 50 flows out the aperture 54 because an end of the needle 50 is blocked with a pin 62 that may be laser welded into the opening. The pin 62 allows for the needle 50 to be non-coring. In an exemplary embodiment, the needle width is about 0.016 inch diameter. A bushing 56 is welded onto the outside diameter of the needle 50 so that needle 50 can be easily mounted in a machine.

Referring to FIGS. 14 and 15, another exemplary embodiment of a needle 150 is illustrated. The needle 150 is similar to the needle 50 described above, and therefore like reference numerals preceded by the numeral “1″ are used to indicate like elements. The needle 150 has a conically-pointed, non-coring tip 152 (i.e., a “pencil point” tip), wherein the included angle a of the tip in cross-section is within the range of about 30.degree. to about 50.degree., preferably about 37.degree. to about 43.degree., and most preferably about 40.degree.. The needle tip further defines at least one axially oblong flow aperture 154 on a side of the needle 150. The aperture 154 is located approximately a distance “d” from an end of the tip 152 of the needle 150. The distance “d” can range from about 0.01 inch to about 0.05 inch and in an exemplary embodiment is about 0.030 inch.

Referring to FIGS. 16 and 17, another exemplary embodiment of a needle 250 is illustrated. The needle 250 is similar to the needles 50 and 150 described above, and therefore like reference numerals preceded by the numeral “2″ are used to indicate like elements. The needle 250 has a conically-pointed, non-coring tip 252 (i.e., a “pencil point” tip), wherein the included angle “a” of the tip in cross-section is within the range of about 33.degree. to about 63.degree., preferably about 50.degree. to about 56.degree., and most preferably about 53.degree.. The needle tip further defines at least one axially oblong flow aperture 254 on a side of the needle 250. The aperture 254 is located approximately a distance “d” from an end of the tip 252 of the needle 250. The distance “d” can range from about 0.01 inch to about 0.05 inch and in an exemplary embodiment is about 0.030 inch. The fluid in the needle 250 flows out the aperture 254 because an end of the needle 250 is blocked with a pin 262 that may be laser welded into the opening, which allows for the needle to be non-coring.

In an exemplary embodiment, the needle/stopper interface is treated to reduce the degree of friction therebetween to further reduce the formation of particles during the needle stroke. In one embodiment, the needle is tungsten carbide carbon coated. In another embodiment, the needle is electro-polished stainless steel. In another embodiment, the needle is Teflon coated. In yet another embodiment, the needle is titanium coated to reduce friction at the needle/stopper interface. In another embodiment, grooves are formed in the outer surface of the needle to vent the displaced gas from the chamber. In one such embodiment, a cylindrical sleeve surrounds the grooves to prevent the stopper material from filling or blocking the grooves (partially or otherwise) and thereby preventing the air and/or other gases within the container from venting therethrough. As may be recognized by those of ordinary skill in the pertinent art based on the teachings herein, the non-coring needles may be made in any of numerous different ways, and may take any of numerous different configurations that are currently known, or that later become known.

In the illustrated embodiment of the present invention, the stopper 40 is preferably made of a thermoplastic/elastomer blend, and may be the same material as those described in the co-pending patent applications and/or patents incorporated by reference above. Accordingly, in one such embodiment, the stopper 40 is a thermoplastic elastomer that is heat resealable to hermetically seal the needle aperture by applying laser radiation at a predetermined wavelength and power thereto, and defines (i) a predetermined wall thickness, (ii) a predetermined color and opacity that substantially absorbs the laser radiation at the predetermined wavelength and substantially prevents the passage of the radiation through the predetermined wall thickness thereof, and (iii) a predetermined color and opacity that causes the laser radiation at the predetermined wavelength and power to hermetically seal the needle aperture formed in the needle penetration region thereof in a predetermined time period of less than or equal to about 5 seconds and substantially without burning the needle penetration region.

In one embodiment, the stopper 40 is formed of a thermoplastic elastomer that is heat resealable to hermetically seal the needle aperture by applying laser radiation at a predetermined wavelength and power thereto, and includes (i) a styrene block copolymer; (ii) an olefin; (iii) a predetermined amount of pigment that allows the stopper to substantially absorb laser radiation at the predetermined wavelength and substantially prevent the passage of radiation through the predetermined wall thickness thereof, and hermetically seal the needle aperture formed in the needle penetration region thereof in a predetermined time period of less than or equal to about 5 seconds; and (iv) a predetermined amount of lubricant that reduces friction forces at an interface of the needle and second material portion during needle penetration thereof. In one such embodiment, the stopper includes less than or equal to about 40% by weight styrene block copolymer, less than or equal to about 15% by weight olefin, less than or equal to about 60% by weight mineral oil, and less than or equal to about 3% by weight pigment and any processing additives of a type known to those of ordinary skill in the pertinent art.

In one embodiment, the stopper 40 is made of a thermoplastic elastomer that is heat resealable to hermetically seal the needle aperture by applying laser radiation at a predetermined wavelength and power thereto, and includes (i) a first polymeric material in an amount within the range of about 80% to about 97% by weight and defining a first elongation; (ii) a second polymeric material in an amount within the range of about 3% to about 20% by weight and defining a second elongation that is less than the first elongation of the first polymeric material; (iii) a pigment in an mount that allows the second material portion to substantially absorb laser radiation at the predetermined wavelength and substantially prevent the passage of radiation through the predetermined wall thickness thereof, and hermetically seal a needle aperture formed in the needle penetration region thereof in a predetermined time period of less than or equal to about 5 seconds; and (iv) a lubricant in an amount that reduces friction forces at an interface of the needle and second material portion during needle penetration thereof

In one embodiment, the pigment is sold under the brand name Lumogen.TM. IR 788 by BASF Aktiengesellschaft of Ludwigshafen, Germany. The Lumogen IR products are highly transparent selective near infrared absorbers designed for absorption of radiation from semi-conductor lasers with wavelengths near about 800 nm. In this embodiment, the Lumogen pigment is added to the elastomeric blend in an amount sufficient to convert the radiation to heat, and melt the stopper material, preferably to a depth equal to at least about 1/3 to about 1/2 of the depth of the needle hole, within a time period of less than or equal to about 5 seconds, preferably less than about 3 seconds, and most preferably less than about 11/2 seconds. The Lumogen IR 788 pigment is highly absorbent at about 788 nm, and therefore in connection with this embodiment, the laser preferably transmits radiation at about 788 nm (or about 800 nm). One advantage of the Lumogen IR 788 pigment is that very small amounts of this pigment can be added to the elastomeric blend to achieve laser resealing within the time periods and at the resealing depths required or otherwise desired, and therefore, if desired, the needle penetrable and laser resealable stopper may be transparent or substantially transparent. This may be a significant aesthetic advantage. In one embodiment of the invention, the Lumogen IR 788 pigment is added to the elastomeric blend in a concentration of less than about 150 ppm, is preferably within the range of about 10 ppm to about 100 ppm, and most preferably is within the range of about 20 ppm to about 80 ppm. In this embodiment, the power level of the 800 nm laser is preferably less than about 30 Watts, or within the range of about 8 Watts to about 18 Watts.

Preferably the material used to form the stopper is selected from materials (i) that are regulatory approved for use in connection with the respective contact lens, solution, and predetermined substance to be added thereto, and preferably for direct contact with each such item, and (ii) that do not leach an undesirable level of contaminants or non-regulatory approved leachables into the contact lens, solution and/or predetermined substance. Exemplary materials for the stopper 40 are selected from the group including GLS 254-071, C-Flex R70-001, Evoprene TS 2525 4213, Evoprene SG 948 4213 and Cawiton 7193, modifications of any of the foregoing, or similar thermoplastic elastomers. As may be recognized by those or ordinary skill in the pertinent art based on the teachings herein, these materials are only exemplary, and numerous other materials that are currently known, or that later become known, equally may be used.

As may be recognized by those skilled in the pertinent art based on the teachings herein, numerous changes and modifications may be made to the above-described and other embodiments of the present invention without departing from its scope as defined in the appended claims. For example, the resealable stopper may be integrally molded with the body such as by co-molding (e.g., over molding the stopper to the filling boss or vice-versa) or insert molding. Alternatively, the resealable stopper may be fused or otherwise melted to the body, or the resealable stopper may be sequentially molded to the body. In addition, the resealable stopper may be made of any of numerous different materials that are currently known, or that later become known for performing the functions of the resealable stopper described herein, such as any of numerous different thermoplastic and/or elastomeric materials, including, for example, low-density polyethylene. Similarly, the stopper may be formed with plural layers, such as an inner layer that is compatible with the contact lens solution and/or predetermined substance within the container, and an outer layer that is needle penetrable and laser resealable. The inner layer of the stopper can be made of vulcanized rubber, silicon, or any of numerous other materials that are currently known, or later become known as being compatible with, or otherwise defining a stable enclosure for the particular contact lens, contact lens solution and/or predetermined substance within the container. In addition, the sealing station may employ any of numerous different types of heat sources that are currently known, or that later become known, for performing the function of the heat sources described herein, such as any of numerous different types of laser or other optical sources or conductive heat sources. Also the contact lens, the contact lens solution or the packing solution, and the predetermined substance added to the container, can be any of numerous different types of contact lenses, solutions, and/or substances that are currently known, or that later become known. Accordingly, this detailed description of the currently preferred embodiments is to be taken in an illustrative, as opposed to a limiting sense.

1. A contact lens carrying case which is discarded once the seal on a housing area that houses contact lens is broken and the contact lens is removed from the housing area, the contact lens carrying case comprising: a contact lens case main unit that includes a housing unit comprising housing areas that include concavities arranged to house contact lenses, and including at least one cover unit that seals the lenses in the housing areas when the at least one cover unit is mounted to the housing unit; and a resealing prevention feature that prevents each housing area from being resealed by the cover units, once each housing area is no longer in a sealed state, wherein the resealing prevention feature prevents each housing area from being resealed by the cover unit by irreversibly changing the configuration of the case main unit when the sealed state is lost, wherein said irreversible change in the configuration of said case main unit is caused by the rotation of a handle component integral to the contact lens carrying case, said rotation of the handle effectuated while said cover unit remains closed thereby enabling the detachment of a portion of members comprising a part of said case main unit, said irreversible change comprising at least one of, a) detachment of the members from the at least one cover unit such that a portion of the members remain in a portion of the case main unit other than the at least one cover unit; or b) detachment of the members from the housing unit such that a portion of the members remain in a portion of the case main unit other than the housing unit.

2. The contact lens carrying case according to claim 1, wherein said irreversible change in the configuration of said case main unit includes the detachment of a part of the members comprising each of said case main unit from the cover unit or/and the housing unit.

3. The contact lens carrying case according to claim 1, wherein the part of the members that detach from said at least one cover unit remains in part of the case main unit other than the at least one cover unit.

4. The contact lens carrying case according to claim 1, wherein the part of the members that detach from said housing unit remains in part of the case main unit other than the housing unit.

5. The contact lens carrying case according to claim 1, wherein both the first housing area and the second housing area are sealed using a single cover unit.

6. The contact lens carrying case according to claim 1, wherein said at least one cover unit seals the housing area by engaging with the housing unit, and said resealing prevention feature constitutes a means for preventing the resealing of the housing area via the cover unit by irreversibly changing the configuration of at least one of the cover unit and the housing unit when the cover unit and the housing unit are no longer engaged.

7. A disposable contact lens carrying case comprising: a case main unit including a cover unit and housing areas, the housing areas having concavities arranged to house contact lenses, and the cover unit arranged so that the cover unit seals the lenses in the concavities of the housing areas when the cover unit is mounted to the housing areas; a resealing prevention feature that prevents each housing area from being resealed by the cover unit once the seal of a housing area has been broken and is no longer in a sealed state, wherein the resealing prevention feature prevents each housing area from being resealed by the cover unit by irreversibly changing the configuration of the case main unit, wherein said irreversible change in the configuration of said case main unit is caused by rotation of a handle component integral to the contact lens carrying case, said rotation of the handle effectuates the detachment of a portion of members comprising a part of said case main unit while said cover unit remains closed, said irreversible change comprising at least one of, a) detachment of the members from the cover unit such that a portion of the members remain in a portion of the case main unit other than the cover unit; or b) detachment of the members from the housing area such that a portion of the members remain in a portion of the case main unit other than the housing area.

8. The contact lens carrying case according to claim 1, wherein said housing unit includes a set of contact lenses stored therein and includes a first housing area that houses a contact lens for the left eye and a second housing area that houses a contact lens for the right eye, as said housing area.
Contact Lens Description
BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention pertains to a contact lens carrying case, and more particularly to a so-called disposable-type carrying case that is discarded once the contact lenses contained therein are removed.

2. Description of the Related Art

In recent years, a so-called disposable-type carrying case has been proposed as a container for housing contact lenses. With this type of disposable-type carrying case, the interior of the case is maintained in a sterile state when new, and the case is discarded after it is used for storing or cleaning the contact lenses. When this type of carrying case is used, the contact lenses are always stored in the sterile interior of the case. Consequently, the carrying case need not be cleaned each time the contact lenses are to be stored or cleaned therein, and the contact lenses can be stored and cleaned in a clean environment.

In order to reliably prevent the user from reusing this type of disposable carrying case, it must be made impossible to seal the case once it has been opened and the contact lenses removed. Accordingly, a method has been proposed in the conventional art whereby the lens housing areas of the case interior are covered by a film, which is affixed to the case main units using an adhesive. This method employs the principle that once the film is removed, the adhesive power of the adhesive weakens due to exposure to the air, thereby preventing the lens housing areas that were covered by the film from being re-sealed. (See, for example, Japanese Patent Laid-Open 2002-142838.)

However, with the conventional method in which the case is sealed using an adhesive, the adhesive can adhere to the fingers when the user attempts to remove the contact lenses, making the case difficult to handle.

A disposable-type carrying case is sometimes marketed as a product together with so-called `disposable contact lenses` intended for only one day’s use, with the lens storage solution already present in the carrying case. In this case, a process whereby the film is affixed to the case main units must be carried out during the product manufacturing stage, and during this affixation process, in order to ensure that the contact lenses remain sealed in the case, the degree of adhesion of the film (for example, the existence of areas of the film that are not adhering to the case main units) must be monitored strictly, which is inconvenient from a manufacturing standpoint.

In addition, no design has yet been proposed for a conventional disposable-type carrying case that reliably prevents the lens housing areas from being resealed using a method other than adhesion.

Accordingly, with the foregoing in view, an object of the present invention is to resolve the problems described above and to realize, via an easy-to-use construction, a disposable-type carrying case in which the lens housing areas cannot be re-closed.

SUMMARY OF THE INVENTION

The present invention is the contact lens carrying case which is discarded, once the seal on a housing area that houses contact lens is broken and the contact lens is removed from the housing area, the contact lens carrying case comprising: a case main unit that includes a housing unit in which is formed the housing area, and a cover unit that seals the housing area by being mounted to the housing unit; and a resealing prevention means that prevents each housing area from being resealed by the cover unit, once the housing area is no longer in a sealed state, wherein the resealing means constitutes means that prevents each housing area from being resealed by the cover unit by irreversibly changing the configuration of the case main unit when the sealed state is lost.

Here, an `irreversible change` means a change that cannot be undone in order to return to the previous state.

According to the contact lens carrying case described above, the configuration of the case main unit is irreversibly changed when the sealed state of the housing areas is lost. Resealing of the housing area by the cover unit is prevented by this irreversible change. Therefore, a non-reusable disposable-type carrying case can be realized via an easy-to-handle construction, and the ease of use of the carrying case can be increased while maintaining the case interior in a hygienic state.

Such an irreversible change in the configuration of the case main unit may consist of the removal of a part of the members comprising the case main unit from the cover unit or the housing unit, or a change in the configuration of the part of the members comprising the case main unit, for example. In the first example, a construction may be adopted in which a part of the members removed from the cover unit may be left on part of the case main unit other than the cover unit, or in which the part of the members removed from the housing unit may be left on part of the case main unit other than the housing unit. Either construction would prevent the removed member from being misplaced or lost.

It is preferred that the housing unit have as housing area a first housing area that houses the contact lens for the left eye and a second housing area that houses the contact lens for the right eye. Such a construction enables a pair of contact lenses to be housed in a single case, and makes the carrying case even easier to handle.

It is also preferred, from the standpoint of ease of handling of the cover, that both the first housing area and the second housing area be sealed using a single cover unit.

It is acceptable if the cover unit seals the housing area by engaging with the housing unit, and if the resealing prevention means prevents the resealing of the housing area via the cover unit by irreversibly changing the configuration of at least one of the cover unit and the housing unit when the cover unit and the housing unit are no longer engaged.

Furthermore, a clamping unit that clamps together the housing unit and the cover unit affixed to the housing unit may be adopted as means to maintain the housing area in a sealed state, and the resealing prevention means may constitute means that prevents resealing of the housing area by irreversibly changing the configuration of the clamping unit and at least one of the cover unit and the housing unit when the clamping unit is no longer in the clamped position.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an explanatory drawing showing a plan view of a contact lens case 10 constituting a first embodiment of the present invention;

FIG. 2A shows a side view of the contact lens case 10 before sealing;

FIG. 2B shows a side view of the contact lens case 10 after sealing;

FIG. 3 is a perspective view showing the components disposed around the end portions 27G and 27H of the cover unit 20B that is integrally formed with a handle 12;

FIG. 4 is a perspective view showing the components by which the cover unit 20B engages with the housing unit 50;

FIG. 5 is an explanatory drawing showing an expanded inverted view of the important components in FIG. 2A;

FIG. 6 is an explanatory drawing showing an expanded view of the important components in FIG. 2B;

FIG. 7 shows the handle 12 of the case main unit 10B in the sealed state when it is rotated in the direction of the arrow P1;

FIG. 8 shows the rotation of the handle 12 while pressure is applied to the top portions 41G and 41H;

FIG. 9 shows the state in which an engaging member 40H is detached from the end portion 27H of the cover unit 20B;

FIGS. 10A and 10B each show a side view of the contact lens case 10 constituting a second embodiment of the present invention from two different directions; and

FIG. 11 is a perspective view showing the state in which the engaging member 40H is secured at two locations on the end portion 27H via two bridges, i.e., a first bridge 29H and a second bridge 28H.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In order to further clarify the construction and operation of the present invention described above, embodiments of the present invention will be described below with reference to specific examples thereof. FIG. 1 is an explanatory drawing showing a plan view of a contact lens case 10 constituting a first embodiment of the present invention, while FIG. 2A is an explanatory drawing showing a side view of the contact lens case 10. This contact lens case 10 is a so-called disposable-type carrying case wherein the cover units 20A and 20B cannot be re-closed once they are opened from the closed state.

As shown in FIG. 1, the contact lens case 10 includes a case main unit 10A that houses the contact lens for the left eye and a case main unit 10B that houses the contact lens for the right eye. The case main units 10A and 10B share a common housing unit 50. As a result, the case main unit 10A is integrally formed with the case main unit 10B.

As shown in FIGS. 1 and 2, housing concavities 54A and 54B that constitute semi-spherical bowl-shaped concavities are formed side by side in the housing unit 50. The left contact lens and right contact lens are housed in these housing concavities 54A and 54B, respectively, together with storage solution or cleaning solution.

Covers 20A and 20B are mounted to the housing unit 50 via folding strips 90A and 90B, respectively. The letters `L` and `R` are affixed to these covers 20A and 20B, respectively, to indicate that the associated contact lens is intended for the left or right eye. The folding strip 90A and cover 20A, as well as the folding strip 90B and cover unit 20B, are integrally formed with the housing unit 50.

The cover units 20A and 20B are formed such that when they are folded over along the v-v line shown in FIG. 1 and rotated approximately 180.degree. in the direction of the arrow D1 shown in FIG. 2A, they cover the housing concavities 54A and 54B, respectively. The bent areas of the folding strips 90A and 90B are thinner than the housing unit 50.

The cover units 20A and 20B that are rotated in this fashion are fastened in the closed position by fastening mechanisms SJ described below. As a result, the housing concavities 54A and 54B are sealed (hereinafter referred to as the `sealed state`) by the cover units 20A and 20B, respectively. FIG. 2B shows the case main unit 10B in the sealed state.

While the housing concavities 54A and 54B are in the sealed state, opening the cover units 20A and 20B causes this sealed state to be broken via the breaking mechanisms TJ described below. The contact lens case 10 as to which the sealed state has been broken has a non-resealable construction in order to prevent contamination of the case due to repeated use, and is discarded after the left and right contact lenses are removed from the housing concavities 54A and 54B.

FIG. 1 shows the case main unit 10B before it has ever been used (hereinafter the `unused state`) and the case main unit 10A in the sealed state. Where both the case main unit 10A and the case main unit 10B are in the unused state, the [contact lens case 10] is formed in the configuration bisected by the t-t line in FIG. 1. Consequently, the case main units 10A and 10B have essentially the same components. Therefore, in the description of the components of the case main units 10A and 10B below, in principle the case main unit 10B will be used as a representative example. Moreover, in FIGS. 1 and 2, identical symbols will be used to indicate components that are common to both the case main unit 10A and the case main unit 10B.

As shown in FIG. 1, a protrusion 53 is formed on the housing unit 50 on the side of the case main unit 10B such that it protrudes upward relative to the inner circumferential wall of the housing concavity 54B (i.e., the direction in which the closed cover unit 20B is located relative to the housing unit 50, hereinafter referred to as `upward` or the `top`) (see FIGS. 2A and 2B). A circumferential groove 52 is formed between this protrusion 53 and the surface 51 of the housing unit 50. At the same time, a cover member 25 that faces the housing concavity 54B when the cover unit 20B is closed is formed on the cover unit 20B of the case main unit 10B, as is a protrusion 24 that protrudes downward relative to the inner circumferential wall of the cover member 20B (i.e., the direction in which the housing unit 50 is located relative to the closed cover unit 20B, hereinafter referred to as `downward` or the `bottom`). A circumferential groove 23 and protrusion 22 are formed in this order between this protrusion 24 and the surface 21 of the cover unit 20B.

Beginning from the situation shown in FIG. 2A, where the case main unit 10B is in the unused state, if the cover unit 20B is closed in the direction of the arrow D1 so as to cover the housing concavity 54B, the protrusion 24 disposed on the side of the cover unit 20B enters the interior of the housing concavity 54B along the inner circumferential wall of the housing concavity 54B. As a result, the housing concavity 54B is covered by the cover member 25. When the cover unit 20B is thereafter completely shut, the protrusion 53 disposed on the side of the housing unit 50 becomes snugly engaged with the circumferential groove 23 disposed on the outer circumference of the protrusion 24, and the protrusion 22 disposed on the side of the cover unit 20B becomes snugly engaged with the circumferential groove 52 disposed on the outer circumference of the protrusion 53. The housing concavity 54B is maintained in an airtight condition by the tight fit between the protrusions and grooves described above. When the cover units 20A and 20B are thereafter closed using the fastening mechanisms SJ composed of engaging members 40G and 40H, concave areas 55G and 55H and the like, the housing concavity 54B enters the sealed state shown in FIG. 2B.

As shown in FIGS. 1 and 2, the case main unit 10B includes a handle 12 that is integrally formed with the end portions 27G and 27H of the cover unit 20B. Fastening mechanisms SJ that maintain the closed state of the cover unit 20B and breaking mechanisms TJ that break the closed state of the cover unit 20B are disposed in the regions around the handle 12 and the end portions 27G and 27H (the regions G1 and H1 shown in FIG. 1) and the regions on the side of the housing unit 50 facing the end portions 27G and 27H of the closed cover unit 20B (the regions G2 and H2 shown in FIG. 1).

The fastening mechanisms SJ and breaking mechanisms TJ are disposed at two locations, i.e., on the inside (the areas G1 and G2 in FIG. 1, on the side nearer to the other case main unit 10A) and the outside (the areas H1 and H2 in FIG. 1, on the side farther from the other case main unit 10A). In this embodiment, the constituent parts of the fastening mechanism SJ and the breaking mechanism TJ that are disposed on the former side (the inside) are indicated by the symbol `G` at the end, while the constituent parts of the fastening mechanism SJ and the breaking mechanism TJ that are disposed on the latter side (the outside) are indicated by the symbol `H` at the end. The fastening mechanisms SJ and breaking mechanisms TJ disposed at the two different locations have essentially the same constructions and functions. Therefore, in the description below, in principle the fastening mechanism SJ and breaking mechanism TJ disposed on the outside of the case main unit 10B will be described as representative examples.

The various constituent parts of the fastening mechanism SJ and the breaking mechanism TJ will be described with reference to FIGS. 3 and 4. FIG. 3 is an explanatory drawing showing a perspective view of the components disposed around the end portions 27G and 27H of the cover unit 20B with which the handle 12 is integrally formed, while FIG. 4 is an explanatory drawing showing a perspective view of the components by which the cover unit 20B is fastened to the housing unit 50. In FIG. 4, the fastening components are shown with the handle 12 of the cover unit 10B removed in order to make the construction of such components easier to understand.

As shown in FIG. 3, openings 26G and 26H are formed in the end portions 27G and 27H of the cover unit 20B, and engaging members 40G and 40H are disposed inside these openings 26G and 26H, respectively. These engaging members 40G and 40H are composed of top portions 41G and 41H and bottom portions 45G and 45H.

The top surfaces 42G and 42H of the top portions 41G and 41H protrude upward above the end portions 27G and 27H. The top surfaces 42G and 42H slant downward so as to face in the direction of the handle 12.

The top portions 41G and 41H are fixed via first bridges 29G and 29H to the inner circumferential walls of the end portions 27G and 27H in which the openings 26G and 26H are formed.

The bottom portions 45G and 45H have an external configuration that is slightly larger than that of the top portions 41G and 41H, and extend downward from the bottom surfaces of the top portions 41G and 41H. The bottom portions 45G and 45H are each divided into two members, i.e., an inner side (the side closer to the surface 21 of the cover unit 20B) and an outer side (the side farther from the surface 21 of the cover unit 20B), by slits 47G and 47H formed in the center thereof, and engaging pieces 46G and 46H are formed on the inner side members.

As shown in FIGS. 3 and 4, an outer notch 30H and an inner notch 31H are formed on the end portion 27H disposed between the engaging member 40H and the handle 12 by eliminating sections of the top surface thereof. These notches 30H and 31H are formed along an axial line parallel to the axis of rotation of the handle 12. In addition, an outer notch 30G and inner notch 31G similar to the notches described above are formed in the end portion 27G disposed between the engaging member 40G and the handle 12.

As shown in FIG. 4, concave areas 55G and 55H are disposed at positions on the housing unit 50 that face the bottom portions 45G and 45H when the cover unit 20B is closed. These concave areas 55G and 55H are large enough to house the bottom portions 45G and 45H. Furthermore, through-holes 57G and 57H that are large enough to permit engagement with the engaging pieces 46G and 46H are formed on the inner sides of the concave areas 55G and 55H (the side of each that is nearer to the other concave area 55H or 55G). In addition, slopes 59G and 59H are formed in the concave areas 55G and 55H at positions at which they face the engaging pieces 46G and 46H when the cover unit 20B is closed.

The construction of the handle 12 will now be explained with reference to FIGS. 3 and 5. FIG. 5 is an explanatory drawing showing an enlarged view of the important components Y1 in FIG. 2A rotated 180.degree. vertically. As shown in these figures, when the handle 12 is mounted to the end portions 27G and 27H, the top surfaces 13G and 13H are higher than the top surfaces 42G and 42H of the engaging members 40G and 40H. The height of these top surfaces 13G and 13H is set at the height at which the walls 14G and 14H that face the engaging members 40G and 40H come into contact with the top surfaces 42G and 42H when the handle 12 rotates in the direction of the engaging members 40G and 40H around an axis consisting of the line that connects the outer notches 30G and 30H and the inner notches 31G and 31H of the end portions 27G and 27H.

In the contact lens case 10 having the construction described above, the fastening mechanisms SJ are composed of the engaging members 40G and 40H disposed on the side of the cover unit 20B and the concave areas 55G and 55H having the through-holes 57G and 57H that are disposed on the side of the housing unit 50. In other words, when the cover unit 20B is closed, the bottom portions 45G and 45H of the engaging members 40G and 40H disposed on the side of the cover unit 20B enter the concave areas 55G and 55H on the side of the housing unit 50. When this occurs, because the engaging pieces 46G and 46H that come into contact with the slopes 59G and 59H are guided by the slanted surfaces thereof to enter the concave areas 55G and 55H, they are smoothly and reliably led toward the interior of the concave areas 55G and 55H. When the cover unit 20B is then closed, the engaging pieces 46G and 46H advance toward the bottom surfaces of the concave areas 55G and 55H while warping toward the slits 47G and 47H due to the contact with the inner walls 56G and 56H, and enter the through-holes 57G and 57H due to elastic force at the time that they reach the positions at which the through-holes 57G and 57H are formed. This causes the engaging pieces 40G and 40H on the side of the cover unit 20B to engage with the concave areas 55G and 55H on the side of the housing unit 50, maintaining the cover unit 20B in the closed state. This engaged state is shown in FIG. 6. FIG. 6 shows an enlarged view of the key components Y2 in FIG. 2B. In addition, when the cover unit 20B is in the closed state, a sufficient clearance is maintained after engagement between the bottommost parts of the bottom portions 45G and 45H and the inner bottom surfaces of the concave areas 55G and 55H.

At the same time, the breaking mechanisms TJ are composed of engaging members 40G and 40H that are engaged with the concave areas 55G and 55H, end portions 27G and 27H that are connected to these engaging members 40G and 40H via first bridges 29G and 29H, and the handle 12. The functions of these various components are explained with reference to FIGS. 6 through 9.

In the state shown in FIG. 6 (the state in which the engaging members 40G and 40H are engaged with the concave areas 55G and 55H), when the handle 12 is lifted upward in the clockwise direction, the handle 12 rotates in the direction of the arrow P1 around an axis consisting of the line that connects the outer notches 30G and 30H and the inner notches 31G and 31H of the end portions 27G and 27H, as shown in FIG. 7. As a result of this rotation of the handle 12, the first bridges 29G and 20H that link the end portions 27G and 27H with the top portions 41G and 41H of the engaging members 40G and 40H is pulled upward in the direction of rotation of the handle 12, and the walls 14G and 14H of the handle 12 come into contact with the foot areas (the bottommost portions of the downward slanting surfaces) of the top surfaces 42G and 42H of the engaging members 40G and 40H.

In FIGS. 6 through 9, because the outer notch 30G and the inner notches 31G and 31H are positioned directly behind the outer notch 30H, they are omitted from the figures. Furthermore, in FIGS. 6 through 8, the hollowed-out area formed in the outer notch 30H is indicated by diagonal lines.

In the state shown in FIG. 7 (the state in which the top surfaces 42G and 42H are in contact with the walls 14G and 14H), when the handle 12 is further lifted upward in the clockwise direction, the handle 12 rotates in the direction of the arrow P1 while pressing diagonally downward in the direction opposite from the handle 12 (in the direction of the arrow Q1 in FIG. 7) against the top portions 41G and 41H of the engaging members 40G and 40H via the walls 14G and 14H.

The rotation of the handle 12 while pressure is applied against the top portions 41G and 41H is shown in FIG. 8. As shown in FIG. 8, the diagonal downward pressure on the top portions 41G and 41H causes the engaging members 40G and 40H to move downward (in the direction of the arrow R1 in FIG. within the concave areas 55G and 55H, whereby the bottommost parts of the bottom portions 45G and 45H come into contact with the inner bottom surfaces of the concave areas 55G and 55H. As a result, the engaging members 40G and 40H can no longer move within the concave areas 55G and 55H in the direction of the arrow R1.

In addition, the diagonal downward pressure exerted on the top portions 41G and 41H causes the engaging members 40G and 40H to move horizontally within the openings 26G and 26H of the end portions 27G and 27H in the direction away from the handle 12 (in the direction of the arrow S1 in FIG. 8), whereby the top portions 41G and 41H of the engaging members 40G and 40H come into contact with the end portions 27G and 27H on the side at which the first bridges 29G and 29H are not formed. As a result, the engaging members 40G and 40H can no longer move in the direction of the arrow S1 within the openings 26G and 26H.

The rotation of the handle 12 that results in this movement of the engaging members 40G and 40H further causes the first bridges 29G and 29H to be lifted upward in the direction of rotation of the handle 12.

During the state shown in FIG. 8 (the state in which the engaging members 40G and 40H cannot move in the direction of the arrows R1 and S1), if the handle 12 is pulled upward in the clockwise direction with force, the handle 12 rotates in the direction of the arrow P2 using as a fulcrum the contact point `fu` disposed between the walls 14G and 14H and the top surfaces 42G and 42H. This rotation of the handle 12 in the direction of the arrow P2 while the engaging members 40G and 40H are fixed in position causes the end portions 27G and 27H that are integrally formed with the handle 12 to rise gradually starting with the parts close to the handle 12. As a result, the first bridges 29G and 29H connected to the parts of the end portions 27G and 27H that are close to the handle 12 are pulled with force in the direction of the arrow P2 while the connection with the top portions 41G and 41H is maintained, resulting in the application of a shearing force to the first bridges 29G and 29H. This shearing force increases in strength as the rotation of the handle 12 in the direction of the arrow P2 progresses, and within a short amount of time the first bridges 29G and 29H are sheared off from the end portions 27G and 27H.

Due to the shearing of the first bridges 29G and 29H, the cover unit 20B detaches from the engaging members 40G and 40H. As a result, the handle 12 can be further rotated in the direction of the arrow P2 and the cover unit 20B can be opened, thereby allowing the contact lenses to be removed from the housing concavities 54A and 54B.

The detachment of the engaging member 40H from the cover unit 20B is shown in FIG. 9. As shown in FIG. 9, the first bridge 29H connected to the end portion 27H of the cover unit 20B is sheared off at the region X. The engaging member 40H that is detached from the cover unit 20B due to this shearing is held on the side of the housing unit 50 while engaging with the concave area 55H. The first bridge 29H remains on the surface of this held engaging member 40H after shearing occurs. As a result of the shearing of the first bridge 29H as described above, the cover unit 20B cannot be returned to its original configuration (i.e., its configuration when the engaging member 40H was connected to the end portion 27H).

Even where the cover unit 20B is closed from the state shown in FIG. 9 (the state in which the engaging member 40H has detached from the end portion 27H of the cover unit 20B), because there is no member that keeps the cover unit 20B fastened to the housing unit 50 (i.e., the engaging member 40H), the cover unit 20B cannot be maintained in the closed state. As a result, the housing concavity 54B can no longer be resealed by the cover unit 20B.

According to the contact lens case 10 of the first embodiment described above, where the sealed state of the housing concavity 54B realized via the closing of the cover unit 20B is broken by the opening of the cover unit 20B, the engaging members 40G and 40H detach from the cover unit 20B due to the breaking of this sealed state. The resealing of the housing concavity 54B by the cover unit 20B is prevented by the detachment of the engaging members 40G and 40H. Therefore, a non-reusable disposable-type carrying case can be realized via an easier-to-handle construction, and the convenience of the carrying case can be increased while maintaining the cleanliness of the carrying case. Furthermore, because the engaging members 40G and 40H that detach from the cover unit 20B remain inside the concave areas 55G and 55H of the housing unit 50, they can be prevented from becoming separated from the contact lens case 10 after they detach.

Moreover, according to the above contact lens case 10, the contact lenses that are inserted in the user’s eyes can be stored in a safer condition. In other words, first, using the contact lens case 10 described above, the fastening mechanisms SJ disposed on the case main unit 10B are lost due to the opening of the cover unit 20B from the closed state. As a result, the user can readily determine from the state of the case main unit 10B after the cover unit 20B is opened (specifically, the state in which the cover unit 20B cannot be maintained in a closed state after it is opened) that the cover unit 10B cannot be reused. Therefore, a situation in which the case is mistakenly reused and the contact lenses are contaminated by microbes or the like can be reliably prevented.

Second, using the above contact lens case 10, it can be clearly seen based on the appearance of the case main unit 10B that the cover main unit 20B has been opened from the closed state. This is because due to the opening of the cover unit 10B from the closed state, the configuration of [the case main unit 10B] changes as a result of the detachment of the engaging members 40G and 40H from the cover unit 20B, thereby preventing the case main unit 10B from being returned to its state prior to the opening of the cover 20B. Therefore, the intentional insertion of foreign matter into the case main unit 10B in which the contact lens is housed can be prevented.

A different construction that combines cleanliness, convenience and safety as described above will be described below as a second embodiment. FIG. 10A is an explanatory drawing showing the side view of a contact lens case 110 constituting a second embodiment of the present invention. The contact lens case 110 shown in FIG. 10 includes essentially the same components as the contact lens case 10 of the first embodiment described above. In FIG. 10, these common components are indicated using in the tens and ones columns the same numbers and letters used in connection with the first embodiment above.

FIG. 10A is a side view equivalent to FIG. 2B, and shows case main units 110A and 110B in the state in which housing concavities 154A and 154B are sealed by cover units 120A and 120B that are bent via folding strips 190A and 190B. Because the folding strip 190A, cover unit 120A, housing concavity 154A and case main unit 110A are disposed behind the folding strip 190B, cover unit 120B, housing concavity 154B and case main unit 110B, they are not shown in the drawing. FIG. 10B is a side view of the folding strip 190B of the case main unit 110B shown in FIG. 10A as seen from the direction of the arrow W.

The contact lens case 110 of the second embodiment has, as in the first embodiment, fastening mechanisms SJ comprising the engaging members 140G and 140H that are disposed on the side of the cover unit 120B and engage inside the concavities 155G and 155H that are disposed on the side of the housing unit 50, such fastening mechanisms SH holding the cover unit 120B in the closed position. At the same time, the contact lens case 110 differs from the contact lens case 10 of the first embodiment in that the breaking mechanisms TJ that break the closed state of the cover units 120A and 120B are disposed on the folding strips 190A and 190B. In other words, as shown in FIG. 10B, a cutaway area 191 formed by notches on either side, as well as a pull tab 192 that is connected to this cutaway area 191 and is exposed to the outside of the case main unit 110B, are formed on the folding strip 190B of the case main unit 110B.

A V-shaped cutout 195B is cut out from the surface of the cover unit 120B near the engaging members 140G and 140H. This cutout 195B is cut out to form an obtuse angle such that its sides are parallel with the line connecting the engaging member 140G and the engaging member 140H, and is formed along the entire outer surface of the cover unit 120B. Similarly, a cutaway area, pull tab and cutout similar to those in the case main unit 110B are also formed in the folding strip 190A of the case main unit 110A and the cover unit 120A.

In the contact lens case 110 having the above construction, the cover units 120A and 120B are not opened from the side of the fastening mechanisms SJ, but from the side of the folding strips 190A and 190B. In other words, by pulling the pull tab 192 along the notches of the cutaway area 191, the cutaway area 191 is torn away from the folding strip 190B, causing the pull tab 192 and the cutaway area 191 to detach from the folding strip 190B. This permits the cover unit 120B to be opened in the direction of the arrow K1 shown in FIG. 10A using the cutout 195B as a rotational axis, allowing the contact lens to be removed from the housing concavity 154B.

In addition, the detachment of the pull tab 192 and the cutaway area 191 prevents the folding strip 190B from returning to its original configuration. Therefore, even where the cover unit 120B is closed after the detachment of the pull tab 192 and the cutaway area 191, the cover unit 120B cannot be maintained in the closed state, and consequently the housing concavity 154B cannot be resealed by the cover unit 120B.

According to the contact lens case 110 of the second embodiment described above, when the sealed state of the housing concavity 154B achieved via the closing of the cover unit 120B is broken, the pull tab 192 and the cutaway area 191 detach from the folding strip 190B as a result thereof. The detachment of the cutaway area 191 prevents the resealing of the housing concavity 154B by the cover unit 120B. Therefore, a non-reusable disposable-type carrying case can be realized using a construction that is easier to handle, and the convenience of the carrying case can be increased while maintaining the cleanliness thereof. Furthermore, as with the contact lens case 10 of the first embodiment described above, the contact lenses that are inserted in the user’s eyes can be stored in a safer condition.

In the second embodiment described above, a construction having no handles 112 may be adopted, and it is acceptable if a different construction for the fastening mechanisms SJ is used.

While the present invention was explained with reference to embodiments, the present invention is not limited thereby, and may be implemented in any fashion within the essential scope of the invention. For example, the first embodiment used the construction in which the engaging members 40G and 40H remain in the concave areas 55G and 55H after detachment, but a construction in which the engaging members 40G and 40H do not remain in the case main units 10A and 10B after detachment may be adopted instead.

In the above embodiments, the engaging members 40G and 40H were secured to the end portions 27G and 27H of the cover units 20A and 20B at a single location via the first bridges 29G and 29H, but they may be secured at two or more locations. An example in which the engaging member 40H is secured to the end portion 27H at two locations via a first bridge 29H and a second bridge 28H is shown in FIG. 11.

In the above embodiments, the engaging members 40G and 40H were disposed on the side of the cover units 20A and 20B, while the concave areas 55G and 55H were disposed on the side of the housing unit 50, but a construction may be adopted instead wherein the engaging members 40G and 40H are disposed on the side of the housing unit 50, while the housing concavities 54A and 54B are disposed on the side of the cover units 20A and 20B.

In the above embodiments, the case main unit 10A including the housing concavity 54A was integrally formed with the case main unit 10A including the housing concavity 54B, and the right and left contact lenses were housed as a pair in the contact lens case 10, but it is acceptable if a construction is adopted wherein the case main units 10A and 10B are separate, and the right and left contact lenses are housed in separate cases.

In the above embodiments, the housing concavities 54A and 54B were covered by two separate cover units 20A and 20B, but a construction may be adopted wherein both housing concavities 54A and 54B are covered by a single cover unit.

Furthermore, while the cover units 20A and 20B are integrally formed with the housing unit 50 in the above embodiments, a construction may be used wherein the cover units 20A and 20B are separate from the housing unit 50 and are mounted thereon in an interlocking fashion.

In the above embodiments, a handle 12 was used as means to break the fastening of the cover units 20A and 20B to the housing unit 50, but a construction may be adopted that does not use handles 12, but wherein the fastening of the cover units 20A and 20B is broken using a finger or nail. For example, in the case of the first embodiment described above, if a finger is inserted between the cover units 20A and 20B and the housing unit 50 of the contact lens case 10 during the closed state, and the end portions 27G and 27H of the cover units 20A and 20B are lifted upward, the engaging members 40G and 40H become detached from the cover units 20A and 20B and the cover units 20A and 20B can be opened.

In the above embodiments, non-resealable contact lens cases 10 and 110 were realized via the detachment of the engaging members 40G and 40H or the cutaway area 191, but a different type of irreversible change other than detachment may be used instead. For example, a construction may be adopted wherein the opening of the cover units 20A and 20B from the sealed state over the case main units 10A and 10B causes part of the case main units 10A and 10B to deform into a configuration that prevents resealing.

In the above embodiments, non-resealable contact lens cases 10 and 110 were realized via an irreversible change in the configuration of the cover units 20A and 20B or the folding strips 190A and 190B, but a non-resealable contact lens case may also be achieved via an irreversible change in the configuration of a part of the case main units 10A and 10B other than the cover units 20A and 20B or the folding strips 190A and 190B.

For example, in the first embodiment, it is acceptable if a construction is used for the fastening mechanisms SJ wherein, instead of the engaging members 40G and 40H and the concave areas 55G and 55H, engaging members belonging to the handles 12 become engaged with the housing unit 50 to keep the cover units 20A and 20B in the closed state, such that the engaging members of the handles 12 become detached from the handles 12 when the cover units 20A and 20B are opened.

In addition, it is also acceptable if a construction is used for the fastening mechanisms SJ wherein, instead of the engaging members 40G and 40H and the concave areas 55G and 55H, clamping units that clamp the housing unit 50 and the cover units 20A and 20B together are used to keep the cover units 20A and 20B in the closed state, such that when the clamping by the clamping units is eliminated, the configuration of the housing unit 50 or of the cover units 20A and 20B, which were clamped by the clamping units, changes due to partial detachment or deformation, thereby disabling re-clamping by the clamping units.

1. A method for producing a pattern for tinted contact lenses, comprising the steps of: a.) defining an inner and an outer pattern boundary; b.) selecting a starting angle, a travel distance, and a change angle; c.) selecting a starting string, an iteration string, and a number of iterations to be executed; d.) generating the pattern using at least one algorithm, wherein the algorithm is fractal in nature; and e.) producing a contact lens comprising the pattern.

2. The method of claim 1, wherein the at least one algorithm is derived from one of chaotic systems, diffusion systems, aggregation systems, L-systems, P-systems, cellular automata.

3. The method of claim 2, wherein the algorithm is derived from an L-system.

4. The method of claim 3, wherein the algorithm is derived from a modified L-system that is a 5.sup.th order L-system constrained to produce a pattern P within a region defined by: R.sub.outer.+-.delta.sub.outer

5. The method of claim 2, wherein the algorithm is derived from a diffusion system.

6. The method of claim 5, further comprising the steps of: a.) defining a boundary for a horizon and a substrate; b.) selecting a maximum and a minimum circle radius; and c.) generating a pattern using the algorithm.

7. A tinted contact lens produced using the method of claim 1.

8. A tinted contact lens produced using the method of claim 2.

9. A tinted contact lens produced using the method of claim 3.

10. A tinted contact lens produced using the method of claim 4.

11. A tinted contact lens produced using the method of claim 5.

12. A tinted contact lens produced using the method of claim 6.
Contact Lens Description
FIELD OF THE INVENTION

The invention relates to tinted contact lenses. In particular, the invention provides methods for designing contact lenses that either enhance or change the color of one or more of a lens wearer’s iris, limbal ring, and pupil.

BACKGROUND OF THE INVENTION

The use of tinted, or colored, contact lenses to either or both alter the natural color of the eye and to mask ophthalmic abnormalities is well known. Typically, these lenses incorporate a pattern in the portion of the lens that overlies one or more of the iris, pupil, and limbal ring of the lens wearer when the lens is on-eye.

The conventional method for providing the pattern is drawing the pattern by hand or by using a computer graphics program. Alternatively, the pattern may be formed by taking a digital image of one or more of an actual iris, pupil or limbal ring and extracting portions of the images for use in a pattern. These methods are disadvantageous in that accurately describing the resulting patterns for purposes of creating tooling for production of lenses incorporating the pattern, application of the pattern to a lens mold, pattern metrology and the like are challenging due to the complex geometries of the patterns.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flow diagram of a method of the invention.

FIG. 2 is a flow diagram of a second method of the invention.

FIG. 3 is pattern produced according to a method of the invention.

FIG. 4 is a second pattern produced according to a method of the invention.

FIG. 5 is a third pattern produced according to a method of the invention.

FIG. 6 is a flow diagram of a third method of the invention.

FIG. 7 is a flow diagram of a fourth method of the invention.

FIG. 8 is a fourth pattern produced according to a method of the invention.

FIG. 9 is a fifth pattern produced according to a method of the invention.

DETAILED DESCRIPTION OF THE INVENTION AND PREFERRED EMBODIMENTS

The invention provides methods for designing patterns for use in tinted contact lenses, methods for the manufacture of such lenses, and lenses incorporating the patterns in which the patterns are generated using algorithms. The resulting patterns, when incorporated into a contact lens, serve to enhance or alter the color of one or more of the wearer’ iris, pupil, and limbal ring. The method of the invention provides an objective description of the pattern for purposes of tooling, metrology and manufacturing of a lens incorporating the pattern.

In one embodiment, the invention provides a method for producing patterns for tinted contact lenses comprising, consisting essentially of, and consisting of the step of generating at least a portion of a pattern using at least one algorithm. For purposes of the invention by “algorithm” is meant a set of rules that produce a set of points and includes, without limitation, one or more mathematical formulae.

In the method of the invention, one or more algorithms are used to generate at least a portion of a pattern useful in a tinted contact lens. Algorithms for use in the invention are fractal in nature. Suitable algorithms may be derived from structures such as, without limitation, chaotic systems, diffusion systems, aggregation systems, L-systems, P-system, cellular automata and the like.

As one example, the algorithm is derived from an L-system. Shown in FIG. 1 is a flow diagram for deriving such an algorithm and producing a pattern according to the invention. In a first step (101), the inner and outer pattern boundaries are defined. The boundaries may be of any suitable size and shape. Typically, the boundaries will be that of the average radius of one or more of the human pupil, iris, and limbal ring. The outer and inner boundaries may be changed by adding or subtracting a small fraction, delta.sub.inner or delta.sub.outer, of the corresponding starting radius to the boundary (102). This change may be made stochastic by multiplying delta.sub.inner or delta.sub.outer by a random number between 0 and 1, the resulting effect of which will be to make the boundary appear more natural. The change may be made, and random variable selected, at each iteration step, meaning at each time a line segment is drawn. Additionally, a starting angle, travel distance, and change angle are randomly selected (103) along with the starting string, iteration string, and number of iterations to be executed (104). The algorithm is then run to generate a pattern (105) and a determination is made as to whether the resulting pattern is acceptable (106). If the pattern is not acceptable, the process is repeated changing some or all of the parameters and constraints.

In a more specific example, an algorithm is derived from an L-system and the boundary conditions limit the graphical commands of the L-system’s symbols to an area that is substantially equal to the area covered by a conventional cosmetic lens iris pattern. Additionally and preferably, a stochastic element is provided to this L-system. More particularly, a 5.sup.th order L-system is constrained to produce a pattern within a region defined by two circles. In other words, the pattern (”P”) is produced within a region defined by: R.sub.outer.+-.delta.sub.outer

The algorithm for this system begins with a starting string, or axiom, composed of symbols representing graphical commands. The commands are used by computer code to draw line segments, defined in units of pixels, that compose a pattern for use in a tinted lens. For example, the axiom may be the symbols “F-F” and, during the first iteration, an iteration string randomly chosen by the designer is substituted for each “F.” The code then executes the command in the new string. In a second iteration, the iteration string is substituted for each “F” in the previous string and the code executes these commands.

For example, if the iteration string for the axiom “F-F” is “F+F+”, after the first iteration the string is “F+F+-F+F+.” After the second iteration, the string is “F+F++F+F+F++-F+F++F+F++.” Subsequent iterations are carried out until a predefined number of iterations, determined by the order of the system, has occurred. For example, 5 iterations would be carried out for a 5.sup.th order L-system. The order used will be determined by observation of which order provides the desired pattern.

Graphical meanings are associated with the symbols for the axiom. For example, the symbols for the axiom above are set forth in the table below.

TABLE-US-00001 Symbol Meaning F Draw line of prescribed travel distance from the previous position to the final position wherein the final position is defined by the direction angle and the travel distance. + Change current angle – turn left by turning angle. & Change current angle – turn right by turning angle. – Change angle by reflecting across horizontal (x) axis.

In the table above, the travel distance is the selected length. The values for the travel distance, or length, of the line segment drawn when the F symbol is encountered, the turning angle, or the change in angle occurring when a “+” or “&” symbol is encountered, the iteration string, and the new starting position of the line segments when a boundary condition violation has occurred are all selected by the designer. Each of these values will be determined by the values that produce a desirable pattern, meaning a pattern that when incorporated into a lens achieves a desirable on-eye cosmetic effect.

The starting position of the first line segment is chosen randomly at a position near the inner circle. If the line segments are to be drawn within R.sub.outer.+-.delta.sub.outer and within R.sub.inner.+-.delta.sub.inner and a line segment is greater than R.sub.outer.+-.delta.sub.outer or less than R.sub.inner.+-.delta.sub.inner, a new starting position for the segments that is within these constraints will be randomly chosen at a distance times a random number between 0 and 1 from R.sub.inner after which the code will continue with the execution of the graphical commands. If a line segment is within R.sub.outer.+-.delta.sub.outer and R.sub.inner.+-.delta.sub.inner no change will be made. In FIG. 2 is a flow diagram of such a method.

FIGS. 3 through 5 are examples of patterns generated by the methods shown in FIGS. 1 and 2. For purposes of these figures, the outer and inner circles are 350 and 150 pixels, respectively. As shown in FIGS. 3 through 5, the inner and outer circle boundaries are fuzzy meaning that, when the final position of each line segment is defined, the algorithm checks to determine whether a boundary that changes randomly about the inner and outer circle boundaries was exceeded. Additionally, there is a stochastic nature to the algorithm used in that, if the boundary condition has been exceeded, a new starting position for the line segment will be selected randomly.

In FIG. 3 is depicted a pattern 10 suitable for use as a pattern in a cosmetic contact lens. The pattern 10 was generated after five iterations using the axiom F-F and the iteration string of F&F&F&F&F+F+F+F+. The starting angle was 180 degrees from the horizontal, the travel distance was 5 pixels, and the turning angle was 45 degrees and the rimover distance was 150 pixels. FIG. 4 depicts pattern 20 generated after 5 iterations and using the same axiom, iteration string, starting angle and travel distance as for FIG. 3, but using a turning angle of 22.5 degrees and a rimover distance of 200 pixels. The pattern 30 of FIG. 5 was generated as was the pattern for FIG. 3 except that a travel distance of 2 pixels was used.

The designs shown in FIGS. 3 through 5 are the result of the use of an algorithm used to draw line segments. As another example, an algorithm may be used to generate patterns similar to a physical process, such as diffusion. For example, a pattern may be developed by launching a defined number of circles and allowing each circle to find its location.

FIG. 6 shows a flow diagram of such a process. In a first step (201), horizon and substrate pattern boundaries, preferably which are circles, are defined. By horizon is meant the position from which the circles are launched. By substrate is meant the position at which the launched circles accumulate. The horizon and substrate circles may be of any radii, but preferably the horizon circle is concentric with and has a larger radius than the substrate circle. The horizon and substrate boundaries may be altered (202) at each iteration step by adding or subtracting a randomly chosen fraction of the corresponding starting horizon or substrate radius. The extent of this randomly chosen fraction will be determined by visually inspecting the impact this alteration has on the resultant pattern.

In this embodiment of the method of the invention, the criteria for selecting the minimum and maximum number of circles to be launched (203) is based on the extent to which the area between the circles is to be filled so as to produce a desirable pattern. This will be determined by visually inspecting the impact made on the resultant pattern when changing the minimum and maximum number of circles. The same criteria is used to select the maximum and minimum radius of the launched circles (204). The algorithm is then run to generate a pattern (205) and a determination is made as to whether the pattern is acceptable (206).

More specifically by way of example and as shown in the flow diagram of FIG. 7, the algorithm may be such that small circles are launched from a circular horizon using random locations and trajectories (301). Each circle is permitted to move until it either encounters another circle (302) or exceeds the R.sub.horizon.+-.delta.sub.horizon boundary (303). If a launched circle comes in contact with another such circle, it is placed at the point of contact and another circle is then launched from that point. If a launched circle moves beyond the R.sub.horizon.+-.delta.sub.horizon boundary, it is removed (304) and another circle is launched or if a launched circle is within the R.sub.horizon.+-.delta.sub.horizon boundary, no change is made (305). Alternatively, the horizon circle’s radius may be randomly changed by a small amount when a query is made as to whether a particle has moved beyond the horizon circle radius.

As a launched circle traverses the region between other circles and the substrate circle, it may collide with a background particle. A background particle is a particle, preferably invisible, that changes the trajectory of one of the circles used to define the pattern. Such a collision is elastic in that the circle’s trajectory may be changed by some random factor due to the collision. The probability of having such a collision may be controlled by use of a variable that acts similarly to a temperature and density variable and, thus, may be considered as a diffusion coefficient.

Along with the collision probability, the designer may vary the horizon and substrate radii and the number of launched circles and their radii. In FIGS. 8 and 9 are shown examples using such an algorithm. For purposes of these examples, the diffusion coefficient was infinite, meaning that there were no background collisions.

In the FIG. 8 is shown pattern 40 generated using the above-described diffusion algorithm, a horizon radius of 750 pixels, a substrate radius of 450 pixels and 100,000 circles each having a radius of 1 pixel. Pattern 50 shown in FIG. 9 was generated using the diffusion algorithm, a horizon radius of 750 pixels, a substrate radius of 550 pixels, and 100,000 launched circles each with a radius of 1 pixel.

Using the method of the invention, patterns for tinted contact lenses may be created, which patterns are defined by one or more algorithms. The patterns may be used in a lens for either enhancing or altering one or more of the wearer’s iris, pupil, and limbal ring color and the elements of the pattern may be translucent or opaque depending on the desired on-eye result. For purposes of the invention, by “translucent” is meant a color that permits an average light transmittance (% T) in the 380 to 780 nm range of about 60 to about 99%, preferably about 65 to about 85% T. By “opaque” is meant a color that permits an average light transmittance (% T) in the 380 to 780 nm range of 0 to about 55, preferably 7 to about 50% T.

The color of the pattern elements may be substantially the same as, or complementary to, each other and the color selected for the pattern elements will be determined by the natural color of the lens wearer’s iris and the enhancement or color change desired. Thus, elements may be any color including, without limitation, any of a variety of hues and chromas of blue, green, gray, brown, black yellow, red, or combinations thereof. Preferred colors for a limbal ring include, without limitation, any of the various hues and chromas of black, brown and gray.

The pattern elements, may be made from any organic or inorganic pigment suitable for use in contact lenses, or combinations of such pigments. The opacity may be controlled by varying the concentration of one or both of the pigment and titanium dioxide used, with higher amounts yielding greater opacity. Illustrative organic pigments include, without limitation, pthalocyanine blue, pthalocyanine green, carbazole violet, vat orange #1, and the like and combinations thereof. Examples of useful inorganic pigments include, without limitation, iron oxide black, iron oxide brown, iron oxide yellow, iron oxide red, titanium dioxide, and the like, and combinations thereof. In addition to these pigments, soluble and non-soluble dyes may be used including, without limitation, dichlorotriazine and vinyl sulfone-based dyes. Useful dyes and pigments are commercially available.

The dye or pigment selected may be combined with one or more of a pre-polymer, or binding polymer, and a solvent to form the colorant used to produce the translucent and opaque layers used in the lenses of the invention. Other additives useful in contact lens colorants also may be used. The binding polymers, solvents, and other additives useful in the color layers of the invention are known and either commercially available or methods for their making are known.

The elements may be applied to, or printed on, one or more surfaces of a lens or may be printed onto one or more surfaces of a mold into which a lens forming material will be deposited and cured. In a preferred method for forming lenses incorporating the designs of the invention, a thermoplastic optical mold, made from any suitable material including, without limitation, cyclic polyolefins and polyolefins such as polypropylene or polystyrene resin is used. The elements are deposited onto the desired portion of the molding surface of the mold. By “molding surface” is meant the surface of a mold or mold half used to form a surface of a lens. Preferably, the deposition is carried out by pad printing as follows.

A metal plate, preferably made from steel and more preferably from stainless steel, is covered with a photo resist material that is capable of becoming water insoluble once cured. The elements are selected or designed and then reduced to the desired size using any of a number of techniques such as photographic techniques, placed over the metal plate, and the photo resist material is cured.

The plate is subsequently washed with an aqueous solution and the resulting image is etched into the plate to a suitable depth, for example about 20 microns. A colorant containing a binding polymer, solvent, and pigment or dye is then deposited onto the elements to fill the depressions with colorant. A silicon pad of a geometry suitable for use in printing on the surface and varying hardness, generally about 1 to about 10, is pressed against the image on the plate to remove the colorant and the colorant is then dried slightly by evaporation of the solvent. The pad is then pressed against the molding surface of an optical mold. If necessary, the mold is degassed for up to 12 hours to remove excess solvents and oxygen after which the mold is filled with lens material. A complementary mold half is then used to complete the mold assembly and the mold assembly is exposed to conditions suitable to cure the lens material used. Such conditions are well known in the art and will depend upon the lens material selected. Once curing is completed and the lens is released from the mold, it is equilibrated in a buffered saline solution.

In a preferred embodiment, a clear, pre-polymer layer is used, which pre-polymer layer overlays the pattern and may form the entirety of the lens’ outermost surface. The clear, pre-polymer layer preferably is first applied to the mold surface and the colorant is subsequently applied to the pre-polymer. The pre-polymer may be any polymer that is capable of dispersing the pigment and any opacifying agent used.

The invention may be used to provide tinted hard or soft contact lenses made of any known lens-forming material, or material suitable for manufacturing such lenses. Preferably, the lenses of the invention are soft contact lenses, the material selected for forming the lenses being any material suitable for producing soft contact lenses. Suitable preferred materials for forming soft contact lenses using the method of the invention include, without limitation, silicone elastomers, silicone-containing macromers including, without limitation, those disclosed in U.S. Pat. Nos. 5,371,147, 5,314,960, and 5,057,578 incorporated in their entireties herein by reference, hydrogels, silicone-containing hydrogels, and the like and combinations thereof. More preferably, the lens is made from a material containing a siloxane functionality, including, without limitation, polydimethyl siloxane macromers, methacryloxypropyl polyalkyl siloxanes, and mixtures thereof, a silicone hydrogel or a hydrogel made of monomers containing hydroxy groups, carboxyl groups, or both and combinations thereof. Materials for making soft contact lenses are well known and commercially available. Preferably, the lens material is acquafilcon, etafilcon, genfilcon, lenefilcon, balafilcon, lotrafilcon, or galyfilcon.

1. A contact lens package, comprising a base member comprising a hydrophobic material and having a bottom surface and a sidewall contacting the bottom surface to form a cavity; a liquid medium located in the cavity; and a silicone hydrogel contact lens without a surface treatment, having an advancing contact angle of less than 66.degree. and located in the liquid medium, the silicone hydrogel contact lens comprising a material effective in reducing the tendency for the lens to stick to the bottom surface of the cavity without requiring an anti-attachment agent selected from the group consisting of a surfactant, a surface modification of the bottom surface, and a combination of a surfactant and a surface modification of the bottom surface, to reduce the tendency of the lens to stick to the bottom surface.

2. The package of claim 1, wherein the hydrophobic material comprises a polyolefin polymeric material.

3. The package of claim 1, wherein the hydrophobic material comprises a polypropylene material.

4. The package of claim 1, wherein the base member is a molded polypropylene element.

5. The package of claim 1, wherein the base member further comprises a flange extending from the cavity.

6. The package of claim 1, wherein the sidewall comprises at least one planar surface and at least one curved surface, each surface substantially perpendicularly oriented to the bottom surface of the cavity.

7. The package of claim 1, wherein the sidewall is oriented at a non-perpendicular angle to the bottom surface.

8. The package of claim 1, wherein the bottom surface is devoid of a ridge or a groove.

9. The package of claim 1, wherein the bottom surface has a planar surface topography.

10. The package of claim 1, wherein the liquid medium comprises saline.

11. The package of claim 1, wherein the liquid medium comprises a phosphate buffer.

12. The package of claim 1, wherein the liquid medium is free of surfactant.

13. The package of claim 1, wherein the liquid medium comprises an amount of a surfactant effective in enhancing the wettability of the contact lens.

14. The package of claim 1, further comprising a seal attached to the base member to maintain the liquid medium in a sterile condition.

15. The package of claim 1, wherein the silicone hydrogel contact lens has an advancing contact angle of less than 60.degree..

16. The package of claim 1, wherein the silicone hydrogel contact lens has a hysteresis less than about 18.degree..

17. The package of claim 1, wherein the silicone hydrogel contact lens has a hysteresis less than about 15.degree..

18. The package of claim 1, wherein the silicone hydrogel contact lens has a hysteresis less than about 10.degree..

19. The package of claim 1, wherein the silicone hydrogel contact lens has a hysteresis about 5.degree. or less.
Contact Lens Description
The present invention relates to contact lenses and more specifically relates to packages, such as blister packs, for containing at least one contact lens.

BACKGROUND

The packaging of hydrophilic contact lenses in a sterile aqueous solution is well known in the contact lens manufacturing technology. In particular, such packaging arrangements generally consist of so-called blister packages which are employed for the storage and dispensing of hydrophilic contact lenses by a medical practitioner or a consumer who intends to wear the contact lenses. Generally, such hydrophilic contact lenses, which may be disposable after a single wear or short-term use, are manufactured from suitable hydrophilic polymeric materials, such as hydroxyethyl methacrylate (HEMA). Generally, such contact lenses must be stored in a sterile aqueous solution, usually in isotonic saline solution in order to prevent dehydration and to maintain the lenses in a ready-to-wear condition.

Heretofore, contact lens manufacturers normally utilized stoppered glass bottles containing sterile saline solutions in which the hydrophilic contact lenses were immersed. Each bottle was sealed with a suitable silicone stopper and provided with a metal closure as a safety seal in the configuration of an overcap. When the contact lens was intended to be removed from the bottle for use by a patient, the metal closure safety seal was required to be initially torn off the bottle, thereafter the stopper withdrawn and the lens lifted out from the bottle through the intermediary by a suitable tweezer or by pouring the contents from the bottle. This entailed the implementation of an extremely complicated procedure, since the contact lens was difficult to grasp and remove from the saline solution contained in the bottle due to the transparent nature of the contact lens which rendered it practically invisible to the human eye.

More recently, containments in the form of blister packages have been developed for hydrophilic contact lenses, and which enable the storage and shipping of the hydrophilic contact lenses in a simple and inexpensive expedient manner, while concurrently facilitating the removal of the contact lens by a practitioner or a patient.

For instance, a blister package which is adapted to provide a sterile sealed storage environment for a disposable or single-use hydrophilic contact lens, wherein the lens is immersed in a sterile aqueous solution, for example, such as in an isotonic saline solution, is described in Martinez, U.S. Pat. No. 4,691,820. Additional contact lens packages are disclosed in U.S. Pat. Nos. 4,691,820; 5,054,610; 5,337,888; 5,375,698; 5,409,104; 5,467,868; 5,515,964; 5,609,246; 5,620,088; 5,695,049; 5,697,495; 5,704,468; 5,711,416; 5,722,536; 5,573,108; 5,823,327; 5,704,468; 5,983,608; 6,029,808; 6,044,966; and 6,401,915.

Contact lens packages are typically formed from hydrophobic packaging materials, such as polypropylene, polyethylene, nylons, olefin co-polymers, acrylics, rubbers, urethanes, polycarbonates, and fluorocarbons.

Silicone hydrogel contact lenses (i.e., contact lenses which comprise a silicone hydrogel material or a hydrophilic silicon containing polymer) can be stored in packages formed of hydrophobic packaging materials. However, since silicone hydrogel contact lenses are typically made of hydrophobic materials, the contact lens will often stick or adhere to the packaging material when a surface of the contact lens and a surface of the packaging material contact. The sticking of the silicone hydrogel contact lens to the package causes many problems, including an increased chance that the lens will tear when removed from the package.

To attempt to reduce the tendency for silicone hydrogel contact lenses to stick to hydrophobic packaging materials, surfactants have been added to the contact lens packaging solution, see U.S. Patent Pub. No. 2005/0171232. Not all surfactants achieve the desired reduced tendency to stick, and some surfactants do not dissolve completely in the lens packaging solution and/or distort certain properties of the lenses.

Another attempt at reducing the tendency for silicone hydrogel contact lenses to stick to hydrophobic packaging materials is to physically or structurally alter the bottom surface of the package cavity. For example, certain packages have been produced that comprise one or more ridges or one or more grooves on the bottom surface of the cavity.

Thus, there remains a need for improved contact lens packages, particularly, contact lens packages that are suitable for storage of lenses, for example, silicon-containing polymeric contact lenses.

SUMMARY OF THE INVENTION

The present invention addresses this need. It has been discovered that the present contact lenses and contact lens packages which comprise a hydrophobic material have a reduced tendency to stick together relative to other silicone hydrogel contact lenses in similar hydrophobic packaging materials. In particular, the present packages and silicone hydrogel contact lenses do not require a surfactant or a surface modification to reduce the tendency of the lens to stick to a surface of the package. Thus, the present packages provide multiple benefits compared to existing packages, such as reduced manufacturing efforts by eliminating the need to provide surface contours on the bottom surface of the contact lens package cavity, and the potential for reduced amounts of surfactant present in the liquid medium containing the contact lens.

In one embodiment, a contact lens package comprises a base member; a liquid medium; and a silicone hydrogel contact lens. In this embodiment, the base member comprises a hydrophobic material and has a bottom surface and a sidewall contacting the bottom surface to form a cavity. The liquid medium is located in the cavity. The silicone hydrogel contact lens is located in the liquid medium. The silicone hydrogel contact lens comprises a material effective in reducing the tendency for the lens to stick to the bottom surface of the cavity without requiring an anti-attachment agent selected from the group consisting of a surfactant, a surface modification of the bottom surface, and a combination thereof, to reduce the tendency of the lens to stick to the bottom surface. The lens and package can be formed from a variety of materials as desired, and the package may have additional elements, as disclosed herein.

In another embodiment, a holder for a contact lens is provided. The holder generally comprises a base member comprising a cavity having an opening and sized to contain a contact lens in contact with, for example immersed in, a liquid medium, for example a sterile solution. The base member further comprises a flange region including a first flange surface at least partially surrounding the opening of the cavity and a substantially opposing second flange surface. The base member further comprises a grip region spaced apart from the cavity opening and including a first grip surface and a substantially opposing second grip surface.

In one such embodiment, the first grip surface extends away from the cavity opening at an angle, for example, to define a continuous curved angle away from the cavity opening. Preferably, the first grip surface extends away from the cavity opening at an angle of greater than 0.degree. and less than 90.degree. relative to a plane containing the cavity opening. Even more preferably, the first grip surface extends away from the flange region at an angle of between about 10.degree. or about 20.degree. or about 30.degree. and about 60.degree., or about 70.degree. of about 80.degree. relative to a plane containing the cavity opening. For example, the first grip surface extends away from the cavity opening at an angle of about 45.degree. relative to a plane containing the cavity opening.

The first grip surface may be a curved surface. For example, the first grip surface may be concave along a major portion of the surface. In some embodiments, the first flange surface is substantially flat and the first grip surface is a curved surface substantially directly adjacent the first flange surface. The first grip surface is located in a recessed position with respect to the first flange surface. The first grip surface may have a contoured shape substantially complementary to the shape of a surface of a human thumb, for example a surface of a tip portion of an adult human thumb. For example, the first grip surface is at least partially defined by a generally spherical surface region. In some embodiments, the first grip surface is defined substantially entirely by a curved surface, for example a surface that is curved in two directions. The first grip surface may be a concave surface.

In some embodiments, the grip region further comprises a second grip surface substantially opposing the first grip surface. Preferably the second grip surface is curved, for example, is convex.

The second grip surface may include a contoured shape substantially complementary to and/or conforming to the first grip surface.

The grip region may further comprise at least one ridge raised from the first grip surface and having a curved length. The grip region may further comprise at least one ridge raised from the second grip surface and having a curved length. The raised ridge of the first grip surface may substantially oppose the raised ridge of the second grip surface.

In one embodiment, the holder is structured and shaped to facilitate comfortable, natural, firm gripping of the holder by a thumb and forefinger of a contact lens wearer. In this embodiment, the first grip surface, which is located on a top side of the grip region, is defined by a concavely curved surface shaped to comfortably accommodate a tip region of a thumb of a human hand. The first grip surface includes embossed or raised portions, for example, one or more ridges, for facilitating manual gripping of the holder. The second grip surface, which is located on an underside of the grip region, opposite the first grip surface, is defined by a convexly curved surface shaped to comfortably accommodate a surface of a crooked or curved forefinger of the same human hand. In this embodiment, the second grip surface is spaced apart from the second surface of the cavity so as to allow sufficient area for placement of the curved human forefinger therebetween. The second grip surface also includes embossed or raised portions, for example, one or more ridges, for facilitating gripping. The raised surfaces on the first grip surface and the raised surfaces on the second grip surface may comprise raised segments having curved lengths.

The base member further comprises a peripheral ridge located at an outer edge of the flange region. The peripheral ridge extends substantially perpendicular to the first flange surface.

In some embodiments, the cavity includes a substantially flat or planar bottom surface which is circumscribed by a curved side surface. The curved side surface may be defined by a generally spherical surface region. In one aspect of the invention, the cavity is contoured to enable a contact lens wearer to remove a contact lens from the cavity by means of the wearer’s fingertip, for example, when the cavity is approached from substantially any rotational angle. For example, the curved region is defined by a uniformly sloped, generally frusto spherical, surface region. For example, the cavity may be somewhat dome shaped, with a flattened bottom surface. Preferably, the curved side surface is defined by a substantially uniform radius of curvature about the generally planar surface region. The cavity is preferably substantially entirely defined by the generally planar region and a generally frusto spherical surface region.

In some embodiments, at least a portion of the cavity surface is textured. The texture is effective to inhibit adherence of the contact lens to the surface of the generally planar region. For example, in one embodiment, the curved side surface of the cavity is smooth relative to the bottom surface of the cavity which is textured. In some embodiments, the planar bottom surface includes a finely ridged or grooved, for example, striated textured surface. As discussed herein, these features may not be required in silicone hydrogel contact lenses that are formed of a material that is effective in reducing the tendency of the silicone hydrogel lens to stick to the surface of the cavity.

The present packages further provide such a holder as described elsewhere herein which includes a contact lens immersed in liquid medium, and a cover assembly secured to the flange region to sealingly close the cavity having the contact lens and liquid medium therein. In some embodiments, the cover assembly comprises a first member sealingly enclosing the cavity and a second member secured to the base member and at least partially covering the first member. For example, in one embodiment, the cover assembly includes a first member sealingly covering the cavity but not the first grip surface and a second member covering the first member and at least a portion of the first grip surface, for example, the entirety of the first grip surface.

In another aspect, the cavity is sized and shaped to accommodate a single contact lens immersed in solution, and is sized and shaped to facilitate removal of the contact lens from the cavity. The cavity is preferably structured to accommodate a lens in a free floating position within the cavity and solution. By “free floating” is meant that the contact lens moves freely in the solution without significantly adhering to surfaces of the cavity.

In yet another aspect, the cover assembly comprises a first member sealingly enclosing the cavity. In another embodiment, the cover assembly comprises the first member sealingly enclosing the cavity and a second member secured to the base member and at least partially covering the first member. The second member may be removably attached to the base member so as to provide a protective, sanitary cover over both the grip surface region and the first member in order to maintain sterility of these features of the invention. In some embodiments, the first cover member is smaller in size than the second cover member. For example, while the first cover member is sized to overlay and seal the cavity opening, the second cover member is sized to overlay and seal the entire upper surface of the base member, including the cavity, the peripheral region and the grip surface region.

Each and every feature described herein, and each and every combination of two or more of such features, is included within the scope of the present invention provided that the features included in such a combination are not mutually inconsistent. In addition, any feature or combination of features may be specifically excluded from any embodiment of the present invention.

These and other aspects of the present invention are apparent in the following detailed description and additional disclosure, particularly when considered in conjunction with the accompanying drawings in which like parts bear like reference numerals.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a contact lens package comprising a base member and a sealing assembly, in accordance with an embodiment of the present invention.

FIG. 2 is a perspective view of the contact lens package shown in FIG. 1, the package now being shown with the sealing assembly removed from the base member.

FIG. 3 is a cross sectional view of the base member shown in FIG. 2 taken along lines 3-3.

FIG. 3A is a perspective view of the contact lens package shown in FIG. 2, the package shown being gripped between a tip of a human thumb and a crooked forefinger.

FIG. 3B is a perspective view of a prior art contact lens package.

FIG. 4 shows the contact lens package shown in FIG. 1, the package now being shown with a portion of a second element of the sealing assembly cut away from the base member, thereby revealing an underlying first element of the sealing assembly.

FIG. 5 is a perspective view of another prior art contact lens package.

FIG. 6 is a perspective view of a contact lens package including a silicone hydrogel contact lens in a cavity of the lens package body, in accordance with another embodiment of the present invention.

DETAILED DESCRIPTION

Turning now to FIG. 1, a contact lens package, in accordance with the present invention, is shown generally at 10.

The package generally comprises a base member 12 and a cover assembly 14. The invention will be more clearly understood and appreciated with reference to FIG. 2 which shows the package 10 shown in FIG. 1 with the cover assembly 14 removed from the base member 12. As shown, the base member 12 includes a cavity 18 for containing a contact lens (not shown) immersed in an amount of a solution. The term “contact lens” as used herein is intended to embrace an ophthalmic lens which, after its removal from a mold assembly in which it is made, is of a structure, size, shape and power that it can be worn on or in the eye of an individual. The base member 12 further includes a peripherally located flange region 20 at least partially surrounding an opening of the cavity 18, and a grip region 22 which is recessed with respect to the flange region 20. The cover assembly 12 sealingly encloses the contact lens and solution within the cavity 18.

The base member 12 is preferably formed of a plastic material which can be formed by injection molding or thermoforming. The plastic material used to make the base member is preferably polypropylene, but can comprise other similar plastic materials, such as, other polyalkylenes, e.g. polyethylene, and polybutylene; polyesters, e.g. PET; polycarbonates; or other thermoplastic materials. In certain embodiments, one or more portions of the base material, particularly in the cavity 18, has a vapor transmission of less than 10 grams/100 square inches/24 hours at 70.degree. F. and 50 percent relative humidity.

One material for forming the base member 12 is a polypropylene homopolymer, for example Polypropylene PPH 10042, which is a nucleated antistatic homopolymer with a high melt flow index of 35 g/10 min. Polypropylene PPH 10042 is marketed by and available through Atofina Petrochemicals or Total Petrochemicals. Thus, the present contact lens packages may comprise a base member 12 formed of a hydrophobic material, such as polypropylene. In certain embodiment, the base member 12 comprises a polypropylene homopolymer having a melt flow index of about 35 g/10 min, a tensile strength at yield of 35 Mpa, an elongation at yield of about 8.5%, and/or a tensile modulus of about 1700 mPA, as determined using the ISO 527-2 method. The present material may also have a flexural modulus of about 1600 mPA as determined using the ISO 178 method, an Izod impact strength (notched) at 23.degree. C. of about 3 kJ/m.sup.2 using the ISO 180 method, a Charpy impact strength at 23.degree. C. (notched) of about 3.5 kJ/m.sup.2 using the ISO 179 method, and/or a Rockwell hardness (R-scale) of about 98 using the ISO-2039-2 method. The present materials may also have a melting point of about 165.degree. C. using the ISO 3146 method, a density of about 0.905 g/cm.sup.3, and/or bulk density of about 0.525 g/cm.sup.3 using the ISO 1183 method.

The flange region 20 is preferably contiguous to the circumference of the cavity 18. The flange region 20 preferably extends about 5 mm from the opening of the cavity 18 to the grip region 22. In the embodiment shown, the overall dimensions of the package 10 are approximately 30 mm wide, about 47 mm long and about 10 mm high. It should be appreciated, however, that the package 10 can have any size and/or shape as long as the aspects disclosed elsewhere herein are met.

The cavity 18 holds in a fluid tight manner, a contact lens and solution. The cavity 18 is bounded by a seal area 25 which is part of the flange region 20. The cover assembly 14 is preferably attached to the base member 12 by heat-sealing in the seal area 25; however, induction-sealing, sonic welding or another bonding system can be used to attach the cover assembly 14 to the base member 12. The total interior volume defined by the cavity 18 and the sealing assembly 12 is about 2.2 ml.

The present invention also provides a contact lens package which includes a contact lens and an amount of solution sealed within the cavity.

In certain embodiments of the present packages, such as the embodiment illustrated in FIG. 1, the contact lenses are hydrophilic lenses. Such hydrophilic lenses may be constructed from one or more monomeric unit components, i.e., monomeric components. For example, and without limitation, the monomeric unit component may comprise hydrophilic monomers which provide –OH, –COOH, –NCO(CH.sub.2).sub.3 (e.g., pyrrolidone) and the like groups. Examples of useful hydrophilic monomeric components include, without limitation, hydroxyalkyl methacrylates, such as hydroxyethyl methacrylate, methacrylic acid N-vinylpyrrolidone, acrylamide, alkyl acrylamides, vinyl alcohol, monomers, such as hydrophilic(meth)acrylates and the like and mixtures thereof, useful for inclusion in hydrophilic silicone polymeric materials, e.g., silicone hydrogels, silicone-containing monomers for polymerization into hydrophilic silicone polymers, siloxanes, such as organosiloxanes and the like and mixtures thereof, silicone-containing acrylates, silicone-containing methacrylates, and the like and mixtures thereof. Preferably, the lens is a hydrogel-containing lens, more preferably a silicone hydrogel-containing lens.

Ophthalmic lenses included in the packages of the present invention may include ophthalmic lenses made from biocompatible, non-hydrogel materials or components. Examples of non-hydrogel materials include, and are not limited to, acrylic polymers, polyolefins, fluoropolymers, silicones, styrenic polymers, vinyl polymers, polyesters, polyurethanes, polycarbonates, cellulosics, proteins including collagen-based materials and the like and mixtures thereof.

The fluid medium or solution contained in the cavity 18 can be any known solution useful for storing contact lenses including water, saline solutions, or buffered aqueous solutions. The contact lens and solution will preferably fill at least 50 percent, more preferably at least 70 percent, and most preferably at least 80 percent of the total volume defined by the cavity 18 and the cover assembly 14.

Referring now specifically to FIGS. 2 and 3, the base member 12 further comprises a rim portion 28 including an upwardly extending ridge 28a substantially surrounding the flange region 20. The rim portion 28 does not entirely circumscribe the holder 12. Referring now specifically to FIG. 2, the rim portion 28 tapers at opposing peripheral edges of the grip region 22 to define terminus 28t adjacent one side of the grip region 22 another opposing terminus 28t adjacent another side of the grip region 22.

In some embodiments of the present packages, the ridge 28a is structured to provide a barrier to contain overflow of solution, for example overflow of solution which can occur when the contact lens is being removed from the cavity 18. The rim portion 28 may further include a downwardly extending ridge 28b. As shown most clearly in FIG. 3, the downwardly extending ridge 28b downwardly extends a distance less that the depth of the cavity 18.

The grip region 22 is at least partially defined by a curved surface between the opposing peripheral edges of the grip region 22. The grip region 22 includes a first grip surface 22a and a substantially opposing second grip surface 22b (shown in FIG. 3). Similarly, the flange region 20 includes a first flange surface 20a and an opposing second flange surface 20b (shown in FIG. 3). The flange surfaces 20a and 20b are substantially planar and both of first grip surface 22a and second grip surface 22b are curved in shape.

In one embodiment, the first grip surface 22a extends away from the first flange surface 20a as a contiguous curve or slope such as shown. Preferably, the first grip surface 22a extends away from the first flange surface 20a at an angle of greater than 0.degree. and less than 90.degree. relative to the first flange surface 20a, (meaning a geometrical plane containing the first flange surface 20a). Even more preferably, the first grip surface extends away from the flange region at an angle of between about 30.degree. and about 60.degree., for example, at an angle of about 45.degree. relative to a plane containing the first flange surface 20a.

The first grip surface 22a may be substantially entirely concavely curved in form while the second grip surface 22b is substantially entirely convex in form.

In this embodiment, the first grip surface 22a is contoured in the form of a concavely curved “thumb grip” for facilitating manipulation of the package by a consumer. Importantly, in this embodiment, in conjunction with the concave curve of the first grip surface 22a for accommodating at least a portion of a human thumb, the second grip surface 22b is convexly curved, particularly at an inner surface portion 22c as shown in FIG. 3, to accommodate a curved or crooked forefinger of a human hand, such that the grip region 22 is easily, naturally and comfortably grippable by a consumer.

These aspects of the invention will be more clearly understood with reference to FIG. 3A, which shows an adult human thumb and forefinger gripping the contact lens holder 10 in a manner that feels comfortable and secure and greatly facilitates opening of the package 10 by the consumer. As shown, the holder 10 is structured to be held by the consumer manually gripping the base 12 as shown in FIG. 3A, for example, with the left hand, while the consumer removes the sealing assembly (not shown in FIG. 3A) with the right hand.

This can be contrasted with a prior art contact lens package 201, shown in FIG. 3B including a well 203 for holding a lens in a fluid medium, and a tab area 205. Tab area 205 is typically gripped between a tip of a thumb and a tip of a forefinger, for example in a “pinching” fashion. This prior art package 201 can not be firmly or even comfortably gripped in the relatively more secure manner of which package 10 is designed to be gripped.

As shown, the grip region 22 is recessed sufficiently deep so that a base surface 30 of the grip region 22 is located generally level with a base surface 32 of the cavity 18. This structure also facilitates handling of the package 10. For example, the stability provided by this design reduces the chance of the contact lens or solution being spilled from the cavity after opening of the cavity 18. For example, it can be appreciated upon referring to FIG. 3 that when the package 10 is placed in an upright position on the tabletop or other level surface, the base 30 of the grip region 22 and the base 32 of the cavity 18 rest against the tabletop surface and maintain the cavity 18 in a level position. In addition, if desired, the package 10 can be opened by placing the package on a tabletop or other surface, and stabilized by pressing the grip region 22 firmly against the tabletop surface, for example using a thumb or finger. Upon so stabilizing the package, the user can then open the cavity 18 by peeling away the sealing assembly 14, for example, in a direction generally away from the grip region 22.

Still referring to FIG. 3, in a related aspect, the grip region 22 comprises raised portion 34 including at least one ridge 34a raised from the first grip surface 22a and having a curved length (see FIG. 4). The grip region 22 further comprises at least one ridge 34 raised from the second grip surface 22b and having a curved length. In the embodiment shown, raised portion 34 includes three ridges 34a raised from first grip surface 22a and three opposing ridges 34b raised from second grip surface 22b. The raised portion 34 facilitates manual gripping of the grip region 22 by a user. The ridges 34a and 34b define curved spaced apart segments of radially concentric circles, for example substantially uniformly spaced apart segments, such as shown most clearly in FIGS. 2 and 4.

In another aspect, the cavity 18 is sized and shaped to accommodate a single contact lens immersed in solution, and is sized and shaped to facilitate removal of a contact lens from the cavity 18. The cavity 18 is preferably structured to accommodate a lens in a free floating position within the cavity and solution. By “free floating” is meant that the contact lens moves freely in the solution without adhering, in any significant degree, to surfaces of the cavity 18.

Referring to FIGS. 2 and 3, the cavity 18 is preferably defined by at least one curved region 36. The cavity 18 may be substantially entirely defined by a generally planar bottom region 38 and the curved side region 36 circumscribing the planar region 38. The generally planar region 38 may include a textured surface (texture not shown), for example a finely grooved or ridged surface, for example a striated surface, effective to reduce the possibility of the contact lens adhering to surfaces of the cavity.

In some embodiments of the invention the texture of the textured surface is visually nearly imperceptible to a naked eye of a person having substantially normal vision capabilities. In other words, the textured surface may appear smooth to a person having substantially normal vision capabilities even though the surface is textured to a significant degree in that, when compared to a relatively smoother surface, the surface will substantially inhibit adherence of the contact lens thereto.

In accordance with another aspect shown most clearly in FIGS. 2 and 3, the cavity 18 is contoured to enable a contact lens wearer to remove a contact lens from the cavity by means of the wearer’s fingertip, for example, when the cavity 18 is approached from substantially any rotational angle. For example, in a preferred embodiment of the invention, the curved side region 36 has a flattened upside down dome shape, for example an inner surface 36a defined by a uniformly sloped, generally frusto spherical surface having a substantially uniform radius of curvature circumscribing an inner surface 38a of the generally planar bottom region 38. The cavity 18 is preferably substantially entirely defined by the generally planar region 38 and the generally frusto spherical surface region 36. In some embodiments of the invention, the inner surface 36a of the curved side region 36 is texturally smooth relative to the inner surface of the bottom region 38.

Referring now to FIGS. 1 and 4, the cover assembly 14 is illustrated as comprising at least two elements, for example at least two different, separate layers of material. For example, in the embodiment of the invention shown, the cover assembly 14 preferably comprises a first member, i.e. first layer 52, and a second member, i.e. second layer 54 overlaying the first member 52. FIG. 4 shows the package 10 with a major portion of the second member 54 removed therefrom in order to more clearly reveal the first member 52 disposed beneath the second member 54. The first member 52 may be made of a laminate material that is heat sealed to the seal region 25 of the base member 12. The second member 54 preferably comprises a foil material, sealed to the rim portion 28 of the base member 12.

The second member 54 may comprise and at least one, for example two, polymer layers, e.g. polypropylene, coating the foil. The foil may comprise aluminum. The polymer coating material on the heat seal side of the foil may be polypropylene. Examples of useful cover layers are described in U.S. Pat. No. 4,691,820 incorporated herein in its entirety by this reference. The second member 54 may be sealed to the base member 12 along an entire circumference of the base member 12 as shown in FIG. 1, so as to provide a sanitary or sterile covering, for example by means of a hermetic seal, over both the first grip surface 22a and the first member 52.

The present packages described hereinabove can be structured to be substantially easier to use than prior art contact lens packages. In use, for example, a user removes the second member 54 by peeling the second member 54 away from the grip region 22. This may be facilitated by tab 54a (FIG. 1). The user then grips the package 10 between thumb and curved forefinger, as shown in FIG. 3A, for example, with the left hand. While the package is so secured, the user then carefully peels away the first member 52 facilitated by tab 52a (FIG. 4), using the right hand, thereby revealing the cavity 18 and the contents therein. The contact lens can then be easily removed from the cavity 18 with a fingertip.

FIG. 5 illustrates another prior art contact lens package 301. Package 301 is a polypropylene blister pack that is used to contain a polyHEMA contact lens in a sterile solution in the cavity 103.

FIG. 6 illustrates a contact lens package in accordance with another embodiment of the present invention. In this embodiment, the contact lens package 110 comprises a body member 112 with a cavity 118. A flange region 120 is shown extending from the cavity 118. A silicone hydrogel contact lens is shown at 113 and is provided in a liquid medium (not shown) in the cavity 118.

The contact lens package 110 is similar to the package illustrated in FIG. 5. However, the contact lens package is formed of a different grade of polypropylene than that of FIG. 5. For example, the contact lens package 110 can be formed from the polypropylene homopolymer PPH10042, disclosed hereinabove. In addition, the contact lens 113 located in the cavity 118 of the contact lens package 110 is a silicone hydrogel contact lens, and not a polyHEMA contact lens which is used in the package shown in FIG. 5.

As discussed in U.S. Patent Pub. No. 2005/0171232, it has been established that silicone hydrogel contact lenses stick to hydrophobic packaging materials, such as polypropylene-based blister packs and the like, unless a surfactant is present in the storage solution containing the silicone hydrogel contact lens. In addition, others have formed grooves or ridges on the bottom surface of the cavity of the packages to reduce the tendency for silicone hydrogel contact lenses to stick to the bottom surface of the cavity.

In contrast, it has been discovered that the present combination of hydrophobic material-based contact lens packages, such as polypropylene-based contact lens packages, and the silicone hydrogel contact lenses disclosed herein have a reduced tendency to stick or adhere to a surface forming the cavity of the present packages without requiring a surfactant or a ridge or a groove in the bottom surface of the cavity. Furthermore, the present lenses do not require a surface modification or surface treatment to make the surfaces of the lenses wettable.

Without wishing to be bound by any particular theory or mechanism of action, it is believed that the present reduced adherence is related to the enhanced wettability of the surfaces of the present lenses relative to existing silicone hydrogel contact lenses. The wettability of a contact lens surface can be related to the advancing contact angle and/or the difference between the advancing contact angle and receding contact angle (e.g., hysteresis). The present contact lenses, even without a surface treatment, have an advancing contact angle less than existing silicone hydrogel contact lenses. For example, the present lenses have an advancing contact angle less than 66.degree.. In certain embodiments, the advancing contact angle is less than about 60.degree., for example, the advancing contact angle may be about 55.degree. or less. In contrast, existing silicone hydrogel contact lenses have an advancing contact angle greater than 66.degree.. In addition, the present contact lenses can have a hysteresis less than about 18.degree.. In certain embodiments, the hysteresis is less than about 15.degree., such as less than about 10.degree.. In certain embodiments, the hysteresis of the present contact lenses is about 5.0.degree. or less. These values can be measured using the captive bubble method in phosphate buffered saline.

Thus, a mechanism for the reduced adherence of the present lenses can be attributed to the enhanced wettability of the surfaces of the present contact lenses relative to the wettability of the surfaces of other different silicone hydrogel contact lenses that are made of different materials and/or in different contact lens molds. For example, the present contact lenses may have a reduced advancing contact angle and/or hysteresis relative to existing silicone hydrogel contact lenses.

Therefore, in accordance with another embodiment of the present packages, it can be understood that a contact lens package comprises a base member having a cavity, a liquid medium located in the cavity, and a silicone hydrogel contact lens located in the liquid medium.

In this embodiment, such as shown in FIG. 6, the base member comprises a hydrophobic material. The base member has a bottom surface 138 and a sidewall 136 contacting the bottom surface 138 to form a cavity 118.

In the illustrated embodiment, the hydrophobic material comprises a polyolefin polymeric material. For example, the hydrophobic material of the base member may be a polypropylene polymer. Thus, the base member can be understood to be a molded polypropylene element.

In certain embodiments, such as the package 110, the bottom surface 138 is devoid of a ridge or a groove. In additional embodiments, the bottom surface 138 has a planar surface topography. Thus, it can be understood that the bottom surface 138 is smooth, and may cause other silicone hydrogel contact lenses to stick to the surface in the absence of any surface modification or the presence of a surfactant.

A liquid medium, such as a sterile packaging solution, is contained in the cavity. The liquid medium can include saline, a buffer, and other suitable components, including wettability enhancing agents and the like. In certain embodiments, the liquid medium is free of a surfactant, such as a surfactant-free medium. In other embodiments, the liquid medium comprises an amount of a surfactant effective to enhance the wettability of the silicone hydrogel contact lens contained in the liquid medium. This amount may be understood to be a wettability enhancing amount of the surfactant, and this amount can be different than the amount used to reduce the tendency of the silicone hydrogel contact lens to stick to the package.

Thus, in one embodiment, the liquid medium of the present packages comprises saline. The liquid medium may also comprise a phosphate buffer. For example, the liquid medium may be a phosphate buffered saline.

The silicone hydrogel contact lenses in this embodiment comprise a material effective in reducing the tendency for the lens to stick to the bottom surface of the cavity without requiring an anti-attachment agent selected from the group consisting of a surfactant, a surface modification of the bottom surface, and a combination thereof, to reduce the tendency of the lens to stick to the bottom surface. Thus, the present silicone hydrogel contact lenses can comprise a material that is different than existing silicone hydrogel contact lenses, such as those materials disclosed in U.S. Pat. Pub. No. 2005/0171232. The reduced tendency to stick associated with the present lenses may be relative to the tendency to stick for different silicone hydrogel contact lenses formed of different materials.

In certain embodiments, the silicone hydrogel contact lens of the present packages has an advancing contact angle of less than about 66.degree., or less than about 60.degree., or less than about 55.degree., and/or a hysteresis less than about 18.degree., or less than about 10.degree., or less than about 5.degree., as described herein. It is believed that the enhanced wettability of the present contact lenses compared to other different silicone hydrogel contact lenses may contribute to the reduced tendency of the silicone hydrogel contact lens to stick to a surface of the cavity of the present packages. In certain embodiments, the present contact lenses comprise contact lens forming materials, as disclosed in U.S. Application No. 60/604,961, filed Aug. 27, 2004 and U.S. Application No. 60/621,525, filed Oct. 22, 2004. For example, some of the present silicone hydrogel contact lenses comprise a plurality of silicon-containing macromers. In certain lenses, the lenses comprise a combination of a polymethylsiloxane methacrylate derivative and a polysiloxanyl dimethacrylate. The lenses may also comprise other components useful in forming silicone hydrogel contact lenses, including without limitation, sulfosuccinates, isocyantes, pyrrolidonones, methacrylates, and acetamides. Silicone hydrogel contact lenses that comprise materials with a reduced tendency to stick to a hydrophobic packaging material without requiring a surfactant or surface modification of a surface of the cavity, can be produced using materials suitable for silicone hydrogel contact lenses and routinely tested for sticking by placing the lenses in the present packages and liquid media. In addition, such lenses can be selected based on the desired advancing contact angle and/or hysteresis, as described herein.

As shown in FIG. 6, the base member 112 of the present packages 110 can comprise a flange 120 extending from the cavity. The flange can be held by a person when removing the contact lens from the package.

The present packages 110 may also comprise a seal similar to that described for the other embodiments herein. The seal can be a cover assembly such as that described in FIGS. 1 and 4 herein. The seal is attached to the base member to maintain the contact lens in a sterile environment until ready for use by a person.

The present packages may comprise a cavity defined by a sidewall that has at least one planar surface 137a and at least one curved surface 137b, each of which is substantially perpendicularly oriented to the bottom surface 138 of the cavity 118. Alternatively, the present packages may comprise a sidewall that is oriented at a non-perpendicular angle to the bottom surface 138, such as the curved surface 36 shown in FIG. 3.

In view of the disclosure herein, the present silicone hydrogel contact lenses can be understood to have a reduced tendency to become attached to the bottom surface of the package body or cavity relative to different silicone hydrogel contact lenses formed of different materials, wherein the reduced tendency is substantially unaffected by the presence of a surfactant in the liquid medium.

The base members of the present packages can be formed using conventional techniques of forming contact lens packages. For example, the base members can be formed using injection molding or thermomolding techniques. In certain situations, the base members will be formed in a strip of two or more base members attached to each other. In one embodiment, the three base members are attached along an edge to form a strip of three blister packs. The cavity in each base member is filled with a liquid medium suitable for storing contact lenses, such as silicone hydrogel contact lenses, in a sterile condition. In certain embodiments, the medium is a surfactant-free medium. In other embodiments, the medium comprises a wettability enhancing amount of a surfactant. After inspecting and placing a contact lens in the liquid medium of a cavity, the base member is sealed, and may be labeled for distribution, storage, and the like.

The contact lenses may be removed from the package by removing the seal and taking the lens out of the liquid medium and placing the lens on or in an eye of an individual.

Certain aspects and advantages of the present invention may be more clearly understood and/or appreciated with reference to the following commonly owned United States Patent Applications, filed on even date herewith, the disclosure of each of which is being incorporated herein in its entirety by this specific reference: U.S. patent application Ser. No. 11/200,848, entitled “Contact Lens Molds and Systems and Methods for Producing Same”; U.S. patent application Ser. No. 11/200,648, entitled “Contact Lens Mold Assemblies and Systems and Methods of Producing Same”; U.S. patent application Ser. No. 11/200,644, entitled “Systems and Methods for Producing Contact Lenses from a Polymerizable Composition”; U.S. patent application Ser. No. 11/201,410, entitled “Systems and Methods for Removing Lenses from Lens Molds”; U.S. patent application Ser. No. 11/200,863, entitled “Contact Lens Extraction/Hydration Systems and Methods of Reprocessing Fluids Used Therein”; U.S. Patent Application No. 60/707,029, entitled “Compositions and Methods for Producing Silicone Hydrogel Contact Lenses”; and U.S. patent application Ser. No. 11/201,409, entitled “Systems and Methods for Producing Silicone Hydrogel Contact Lenses”.

While this invention has been described with respect to various specific examples and embodiments, it is to be understood that the invention is not limited thereto and that it can be variously practiced within the scope of the following claims.

1. A contact lens having a top, a bottom, a rotational axis, a front surface and a base surface, the front surface including a plurality of zones, comprising: an optical zone having a lower edge, including: a distance vision zone having a curvature range that provides distance vision correction and having a first area that is sufficient to overlay a substantial portion of a pupil of a user and disposed in a first position within the optical zone so that the user’s pupil is substantially subtended by the distance vision zone when the user is gazing at a substantially horizontal point in primary gaze; a near vision zone, extending radially outward from the distance vision zone, having a second curvature range that provides near vision correction and having a second area that is sufficient to overlay a substantial portion of a pupil of a user and disposed in a second position within the optical zone so that the user’s pupil is substantially subtended by the near vision zone when the user is gazing at a near vision point below the substantially horizontal point in down-gaze; and a ledge zone disposed below the optical zone, that includes an undercut portion extending outwardly from the base surface to the front surface to enable engagement with a lower eyelid of a user and thereby provide vertical translation support for the contact lens when being worn by the user.

2. The lens of claim 1, further comprising a transition zone extending from the lower edge of the optical zone to the upper edge of the ledge zone that provides a smooth transition from the ledge zone to the optical zone.

3. The lens of claim 1, further comprising a bevel zone, extending radially outward that tapers to a narrow end.

4. The contact lens of claim 1, wherein the distance vision zone has a center that is offset from the rotational axis of the contact lens.

5. The contact lens of claim 1, wherein the distance vision zone has an oval shape.

6. The contact lens of claim 1, wherein said lens has a thickness profile that increases along the vertical meridian.

7. The lens of claim 6, wherein said lens has a thickness profile that is symmetric about the vertical meridian.

8. The lens of claim 1, wherein the height of said ledge is between about 300-um and about 1200-um along the inferior vertical meridian.

9. The lens of claim 1, wherein the height of said ledge is about 700-um.

10. The lens of claim 1, wherein the ledge has an angular range between about 25 degrees and about 70 degrees measured from the vertical.

11. The lens of claim 1, wherein the angle of the ledge is about 50 degrees to the vertical.

12. The contact lens of claim 3, wherein the distance vision zone has an oval shape.

13. The contact lens of claim 1, wherein the near vision zone is substantially concentric with the rotational axis and extends radially outward from the distance vision zone.

14. The lens of claim 1, wherein said lens is capable of large amplitude translation in the range of about 2 mm to about 5 mm.

15. The lens of claim 1, wherein said lens is capable of large amplitude translation in the range of about 3 mm to about 5 mm.

16. The contact lens of claim 1, wherein the contact lens is comprised of soft contact lens material.

17. The contact lens of claim 16, wherein the soft contact lens material comprises a silicon hydro-gel.

18. The contact lens of claim 16, wherein the soft contact lens material comprises HEMA.

19. A mold capable of creating a lens wherein said created contact lens has a top, a bottom, a rotational axis, a front surface and a base curve, the front surface including a plurality of zones, comprising: an optical zone having a lower edge, including: a distance vision zone having a curvature range that provides distance vision correction and having a first area that is sufficient to overlay a substantial portion of a pupil of a user and disposed in a first position within the optical zone so that the user’s pupil is substantially subtended by the distance vision zone when the user is gazing at a substantially horizontal point in primary gaze; a near vision zone, extending radially outward from the distance vision zone having a second curvature range that provides near vision correction and having a second area that is sufficient to overlay a substantial portion of a pupil of a user and disposed in a second position within the optical zone so that the user’s pupil is substantially subtended by the near vision zone when the user is gazing at a near vision point below the substantially horizontal point in down-gaze; and a ledge zone disposed below the optical zone, that includes an undercut portion extending outwardly from the base curve to the front surface to enable engagement with a lower eyelid of a user and thereby provide vertical translation support for the contact lens when being worn by the user.

20. A method of making a lens capable of large amplitude translation comprising the steps of: cutting a first surface in lens material, wherein said first surface comprises a base curve, including an undercut, wherein said undercut is designed to be engaged by a lower eyelid; supporting said undercut; transferring said lens material; and cutting a second surface, wherein said second surface comprises a front surface; wherein the undercut extends outwardly from the base curve to the front surface.

21. The method of claim 20, wherein said supporting step further comprises adding blocking material behind the base curve and undercut.

22. The method of claim 20, wherein said second cut removes material from the superior boundary of the lens to produce an oblong lens shape.

23. A method of making a lens mold capable of creating a lens with large amplitude translation comprising the steps of: cutting a first surface in lens mold material, wherein said first surface comprises a male mold, including an undercut; supporting said undercut; transferring said lens mold material; and cutting a second surface, wherein said second surface comprises a female mold; wherein the undercut extends outwardly from the first surface to the second surface.
Contact Lens Description
The present invention is directed to a contact lens design where the optics position relative to the pupil is controlled by the lens relationship to the lower lid. More specifically, the present invention provides a lens design that allows large amplitude translation on the eye through use of an undercut ledge.

BACKGROUND OF THE INVENTION

Contact lenses are widely used for many different types of vision deficiencies. These include defects such as near-sightedness and far-sightedness (myopia and hypermetropia, respectively), and defects in near range vision usually associated with aging (presbyopia). Current opinion holds that presbyopia occurs as a person ages when the lens of eye begins to crystallize and lose its elasticity, eventually resulting in the eye losing the ability to focus on nearby objects.

Some presbyopic persons have both near vision and far vision defects, requiring bifocal lenses to properly correct their vision. Many people prefer wearing contact lenses to correct their vision rather than bifocal eye glasses.

A typical single vision contact lens has a focus, which is the point on which parallel rays of light focus when the lens is placed perpendicular to the parallel rays, and an optical axis, which is an imaginary line drawn from the focus to the center of the lens. A posterior surface fits against the cornea and an opposite anterior surface has a vision surface that focuses light to correct the eye’s vision. In the case of a typical spherical lens, the vision surface has a single radius of curvature that is the distance from any point on the vision surface to a point on the optical axis referred to as the center of curvature. A bifocal lens has at least two vision surfaces on the anterior surface of the lens: a distance vision surface, for gazing at far off objects, and a near vision surface, for gazing at close objects (e.g., while reading).

Effective use of a bifocal contact lens requires translation of the eye between vision surfaces when the eye changes from gazing at an object at a distance to gazing at a nearby object. In such a situation, the pupil must move from being subtended by the distance vision surface to being subtended by the near vision surface.

In designing a lens, translation is of particular importance. Most lenses have difficulty translating across the surface of the eye when the visual direction of the eye changes from horizontal gaze distance vision to down gaze near vision. This is due to the ability of a soft contact lens to conform closely to the shape of the cornea. For this reason, soft translating bifocal contact lenses are uncommon. Thus, users who desire bifocal contact lenses are usually limited to using the more uncomfortable hard lenses, while those who wish to wear soft contact lenses are usually limited to wearing mono-focal lenses.

Therefore, there is a need for a soft bifocal contact lens that supports translation across the surface of the eye when the eye changes position from distance vision to near vision. Lenses with a translation “ridge” on the front surface have been produced; however, if the ridge feature does not have an undercut, the lid may not engage the lens and hence, the lens translation amplitude may be insufficient, resulting in poor bifocal performance.

If the ridge is located close to the edge, on a steeper position of the lens, the lid tends to roll over the ridge feature and the lens does not translate. If the ridge is positioned nearer to the center of the lid, where the lid can engage the ridge, the lower lid may not provide enough movement for effective amplitude of the lens translation.

An undercut features currently require slides in the mold bases during the injection molding process, which prevents use of high volume mold manufacture.

SUMMARY OF THE INVENTION

The present invention includes a method for manufacturing a translating lens as well as a design for translating lens. The contact lens of the present invention preferably has a top, a bottom, a rotational axis, a front surface and a base surface. The front surface includes a plurality of zones, one of which is an optical zone having a lower edge with a distance vision zone having a curvature range that provides distance vision correction and having a first area that is sufficient to overlay a substantial portion of a pupil of a user and disposed in a first position within the optical zone so that the user’s pupil is substantially subtended by the distance vision zone when the user is gazing at a substantially horizontal point in primary gaze. In another embodiment, the distance vision zone may have a center that is offset from the rotational axis of the contact lens. In a related embodiment, the distance vision zone may be in the shape of an oval.

The front surface also has an optical zone with a near vision zone, extending radially outward from the distance vision zone, having a second curvature range that provides near vision correction and having a second area that is sufficient to overlay a substantial portion of a pupil of a user. This near vision zone is preferably disposed in a second position within the optical zone so that the user’s pupil is substantially subtended by the near vision zone when the user is gazing at a near vision point below the substantially horizontal point in down-gaze. In a related embodiment, the near vision zone may be substantially concentric with the rotational axis and may extend radially outward from the distance vision zone.

A ledge zone is preferably disposed below the optical zone and includes an undercut portion extending outwardly from the base surface to the front surface to enable engagement with a lower eyelid of a user to provide vertical translation support for the contact lens when being worn by the user. In one embodiment of the present invention, the height of the ledge may be between about 300-um and about 1200-um along the inferior vertical meridian. In a more preferred embodiment, the height of the ledge may be 700-um. In a related embodiment, the ledge may have an angular range from about 25 degrees to 70 degrees as measured from the vertical. In a preferred embodiment, the angle of the ledge is about 50 degrees from the vertical.

In one embodiment of the present invention, the lens may also have a transition zone that extends from the lower edge of the optical zone to the upper edge of the ledge zone and provides a smooth transition from the ledge zone to the optical zone. In a related embodiment the lens has a bevel zone that preferably extends radially outward and tapers to a narrow end. In still another embodiment, a lens of the present invention may have a thickness profile that increases along a vertical meridian. In a related embodiment, the lens may have a thickness profile that is substantially symmetric about the vertical meridian.

Lenses of the present invention may be made of a silicon hydrogel or HEMA. Lenses of the present invention are preferably capable of large amplitude translation. In one embodiment, the lens is capable of translating about 2 mm to about 5 mm. In a preferred embodiment, the lens is capable of translating about 3 mm to about 5 mm.

The present invention also includes a mold that is capable of creating the lens of the present invention. Additionally, the present invention includes a method of making a lens capable of large amplitude translation. This method includes cutting a first surface in lens material, the first surface including a base curve with an undercut designed to be engaged by a lower eyelid; supporting the undercut; transferring the cut lens material; and cutting a second front surface. In another embodiment, the supporting step may include adding blocking material behind the first cut surface. In still another embodiment, the second cut may remove material from the superior boundary of the lens to produce an oblong lens shape.

The present invention also includes a method of making a lens mold capable of creating a lens with large amplitude translation. This method includes cutting a first surface in lens mold material, the first surface including a male mold with an undercut; supporting the undercut feature of the mold; and; and cutting a second front surface, which is a female mold.

These and other aspects of the invention will become apparent from the following description of the preferred embodiments taken in conjunction with the following drawings. As would be obvious to one skilled in the art, many variations and modifications of the invention may be effected without departing from the spirit and scope of the novel concepts of the disclosure.

DESCRIPTION OF THE DRAWINGS

FIG. 1A is a front elevational view of one embodiment of the invention.

FIG. 1B is a cross-sectional view, exaggerated along the horizontal axis, of the embodiment shown in FIG. 1A, taken along line 1B-1B.

FIG. 1C is a detail portion of FIG. 1B.

FIG. 2A is a side elevational view of an uncut button of lens material mounted on a spindle.

FIG. 2B is a side elevational view of the button of FIG. 2A after a first surface has been cut.

DETAILED DESCRIPTION OF THE INVENTION

Reference now will be made in detail to the embodiments of the invention. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment, can be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present invention cover such modifications and variations as come within the scope of the appended claims and their equivalents. Other objects, features and aspects of the present invention are disclosed in or are obvious from the following detailed description. It is to be understood by one of ordinary skill in the art that the present discussion is a description of exemplary embodiments only, and is not intended as limiting the broader aspects of the present invention.

A preferred embodiment of the invention is now described in detail. Referring to the drawings, like numbers indicate like parts throughout the views. As used in the description herein and throughout the claims, the following terms take the meanings explicitly associated herein, unless the context clearly dictates otherwise: the meaning of “a,” “an,” and “the” includes plural reference, the meaning of “in” includes “in” and “on.”

As shown in FIGS. 1A-1C, one embodiment of the invention is a contact lens 100 having top 108, a bottom 109, a rotational axis 102, an posterior surface 104 and an opposite anterior surface 106. The anterior surface 106 may include an optical zone 110, a transition zone 140, a ledge 150 and an undercut 158. The optical zone 110 has a lower edge 114 and includes a distance vision zone 120 and a near vision zone 130. The base (posterior) surface of the lens may have a circular boundary edge, from which, a ledge protrusion is extended from the inferior half of the lens. The base surface, less the ledge feature, may be rotationally symmetrical or may include a toric or biconic optical surface that is blended into a rotationally symmetrical base surface outer portion.

The distance vision zone 120 has a first curvature range that provides distance vision correction for the user. The area of the distance vision zone 120 is sufficient to overlay a substantial portion of a pupil 106a of a user (i.e. cover at least 50% of the pupil). The distance vision zone 120 is disposed so that the user’s pupil is substantially subtended by the distance vision zone 120 when the user is gazing at a substantially horizontal point in primary gaze. Typically, the distance vision zone 120 will be offset from the rotational axis 102. This is so that the pupil 106 will be substantially subtended by the near vision zone 130 when the eye 107 is viewing in downgaze (e.g., when the eye 107 is engaged in reading). The distance a from the center 102 to the bottom of the distance vision zone 120 should be the minimum distance that allows the pupil 106a to be substantially subtended by the distance vision zone 120 when gazing at the horizon. This may result in the distance vision zone 120 having an oval shape. The distance zone 120 preferably provides vertical coma during downward gaze, when the lens translates inferiorly.

A blend zone preferably exists between the distance zone 120 and the near vision zone 130. This blend zone preferably includes surface inflection and a high relative curvature as compared to the curvature of the optical zone. Because optical power is proportional to curvature, light refracted by the blend zone is refracted away from the fovea.

A vertical meridian extends from the top of the lens 108 to the bottom of the lens 109. In the present invention, the optical zone is preferably located along the vertical meridian, which is preferably greater than about 9 mm in length. In a more preferred embodiment, the length of the optical zone is about 10.5 mm. As shown in FIG. 1B, the lens has a thickness profile. In a preferred embodiment, the thickness profile increases from the top of the lens 108 to the bottom of the lens 109, resulting in greater lens thickness towards the bottom of the lens. The lens also has a horizontal meridian that extends from the left side of the lens to the right side of the lens. In a preferred embodiment, the thickness profile along the horizontal meridian is substantially symmetric.

The near vision zone 130 may be substantially concentric with the rotational axis 102 and extends radially outward from the distance vision zone 120. The near vision zone 130 has a second curvature range that provides near vision correction for the user. The area of the near vision zone 130 is sufficient to overlay a substantial portion of the pupil 106b. The near vision zone 130 is disposed so that the user’s pupil 106b is substantially subtended by the near vision zone 130 when the user is gazing at a near vision point below the substantially horizontal point in down-gaze (e.g., while reading). Both the distance vision zone 120 and near vision zone 130 may be placed either on the posterior surface 104 or the anterior surface 106 of the lens 100.

Referring to FIGS. 1A and 1B, the ledge 150 provides vertical translation support for the lens 100. Such support may allow the lens to translate in the range of about 2 mm to about 5 mm, preferably in the range of about 3 mm to 5 mm. The ledge 150 has a front portion 156 and an undercut lower edge 158. The ledge 150 is located below the optical zone 110. Undercut lower edge 158 extends between the front surface and base curve of the lens and is situated at an angle to front portion 156. Undercut lower edge 158 enables engagement with the user’s lower eyelid 105. Thus, when the eye 107 moves in a downward direction, the ledge, specifically, undercut lower edge 158, engages the lower eyelid 105 and supports the lens 100, thereby allowing translation of the lens 100 across the surface of the eye 107.

The height of the ledge, measured as the thickness along the inferior vertical meridian at the edge, is preferably between about 300 um and about 1200 um. In a preferred embodiment, the height of the lens is about 700-um. The angle of the ledge from the vertical may range from about 25 to about 70 degrees. In preferred embodiment, the height of the ledge, to vertical, is about 50 degrees.

The transition zone 140 provides a smooth transition from the ledge 150 to the optical zone 110. The transition zone 140 extends from the lower edge 114 of the optical zone 110 to the upper edge of the ledge 156. This “surface blending,” just above the ledge, may be concave (if the maximum thickness is at the edge) to flat, along the inferior vertical meridian.

The lens may also include other features normally associated with contact lenses. For example, the prism of the lens will typically be about 200 um from top to bottom

For added comfort, the lens 100 may also include a bevel 170. Bevel 170 may be a variable reverse bevel on the base curve or fully tangent surface. The lens may also have an offset progressive to add intermediate vision in primary gaze. Virtually any optics may be used in conjunction with the present lens design. For example, one embodiment of the present invention may have an inferior offset progressive zone. Another embodiment may include optics that are created with a combined coma-like aberration and progressive profile. In still other embodiment, the lens design may include astigmatic correction on either the front surface or the base surface of the lens. In another embodiment, the lens may have greater than one diopters of negative spherical aberration, for a 6 mm pupil, on the distance zone.

The present lens design is designed such that the lens, tools, or molds can be fabricated via an ophthalmic lathe or its equivalent.

A lens 100 according to the invention typically would be made from a soft contact lens material, such as a silicon hydrogel or HEMA. Although, it will be understood that any lens described above comprising any soft contact lens material would fall within the scope of the invention.

A contact lens according to the invention could be constructed using a conventional contact lens molding process or can be cut on a lathe. In an embodiment using a molding process, the mold or the mold tools may be formed on a conventional computer-controlled cutter in conjunction with a lathe, of the type conventionally used in making master casts of contact lenses. Irrespective of whether the lens, the lens mold, or the mold tools are lathed, the lathing process may be similar as described herein for a lens. As such, the discussion below is exemplary only and should not be limited solely to the manufacture of a lens; rather, the following process may be used for a lens, a lens mold, or a mold tool.

As shown in FIG. 2A, a material 200 is mounted on a spindle 220 and is rotated around a rotational axis 202 in a pre-selected direction A. Specifically, the material may be in the shape of a button and clamped or otherwise attached to a pin. Initially, as shown in FIG. 2B, at least one first surface 210 is cut onto the outer surface 206 of the blank or button 200. The first surface 210 is preferably the posterior surface or base curve, which preferably includes the undercut feature of the lens of the present invention (ledge zone). During this process, a shoulder clamp is preferably used to block off the edges of the button. Additionally, wax, or another blocking material that does not scratch the surfaces of lenses, lens molds, or mold tools may be used to block the cut base curve during transfer. The blocking material may also provide support for the undercut feature. After the first surface is cut, the partially formed lens is transferred such that the second side, or anterior surface, may be cut. During the transfer the blocking material remains in place to prevent damage to the first cut surface. Additionally, keys or slots may be used to ensure that the lens remains in proper orientation relative to the spindle. This is particularly important in lenses that are aspherical. The front surface is cut in the same general manner as the back surface, except that the optical zone, the transition zone, and the bevel zone may be cut on the front surface. In an alternative embodiment, these zones may be cut on the back surface. The various vision surfaces may be cut in the lens, lens mold, or mold material by controlling the depth of the cutting instrument (as with a conventional computer control mechanism) as the material rotates.

During the second cut to the front surface, the diameter of the lens, lens mold and/or mold tools, may be cut to produce a pronounced undercut resulting in an oblong shape. Removing some of the diameter of the lens may provide better stability and increased translation. The boundary of the inferior half of the lens may vary with azimuthal angle such that the boundary is not circular and the edge does not lie in a plane. In a preferred embodiment, the boundary of the lens in the superior half is symmetrical and lies in the same plane. In another embodiment, the lens may have an edge round that varies as a sinusoid around, at least, the superior half of the lens. In an embodiment of the present invention in which a mold is created, the mold is preferably created such that lenses created by the mold may have an edge round that varies as a sinusoid around, at least, the superior half of the lens.

The above described embodiments are given as illustrative examples only. It will be readily appreciated that many deviations may be made from the specific embodiments disclosed in this specification without departing from the invention. Accordingly, the scope of the invention is to be determined by the claims below rather than being limited to the specifically described embodiments above.

1. A soft hydrogel contact lens having a tensile modulus less than about 140 psi, oxygen transmissibility of at least about 70 barrers/mm and a dynamic coefficient of friction of less than about 0.01 when measured at a sliding speed of 10 cm/second, wherein said contact lens comprises at least one lubricious polymer in or on said contact lens, provided however, when said lubricious polymer is coated on said contact lens, said lubricious polymer is not polyacrylic acid or poly(N,N-dimethylacrylamide).

2. The contact lens of claim 1 wherein said oxygen transmissibility is at least about 85 barrers/mm.

3. The contact lens of claim 1 further comprising an advancing dynamic contact angle of less than about 90.degree..

4. The lens of claims 1 further comprising a water content of at least about 30%.

5. The lens of claim 1 wherein said oxygen transmissibility is at least about 80 barrers/mm.

6. The lens of claim 2 wherein said oxygen transmissibility is at least about 90 barrers/mm.

7. The lens of claim 1 wherein said oxygen transmissibility is at least about 110 barrers/mm.

8. The lens of claim 1 wherein said oxygen transmissibility is at least about 140 barrers/mm.

9. The lens of claim 3 wherein said advancing dynamic contact angle is less than about 80.degree..

10. The lens of claim 3 wherein said advancing dynamic contact angle is less than about 70.degree..

11. The lens of claim 4 wherein said water content is between about 30% and about 50%.

12. The lens of claim 6 wherein said lens further comprises a water content between about 30% and about 50%.

13. The lens of claim 1 further comprising a tensile modulus of less than about 120 psi.

14. The lens of claim 1 further comprising a tensile modulus of less than about 100 psi.

15. The lens of claim 1 further comprising a tensile modulus of about 40 to about 100 psi.

16. The lens of claim 2 wherein said lens is formed from a silicone hydrogel.

17. The lens of claim 16 wherein said silicone hydrogel is formed from a reaction mixture comprising at least about 20 weight % silicone containing components.

18. The lens of claim 16 wherein said silicone hydrogel is formed from a reaction mixture comprising between about 20 and about 70 weight % silicone containing components.

19. The lens of claim 17 wherein said reaction mixture comprises at least one monofunctional silicone containing component and less than about 10 mmol multifunctional components/100 g reactive components.

20. The lens of claim 19 wherein said multifunctional components comprise less than about 7 mmol/100 g of the reactive components.

21. The lens of claim 19 wherein said monofunctional silicone containing component is selected from the group consisting of polysiloxanylalkyl(meth)acrylic monomers, mono-functional polydimethylsiloxanes and mixtures thereof.

22. The lens of claim 19 wherein said multifunctional components comprise multifunctional silicone containing components.

23. The lens of claim 22 wherein said multifunctional silicone containing components are selected from the group consisting of poly(organosiloxane) prepolymer, multifunctional silicone-containing vinyl carbonate and vinyl carbamate monomers, polyurethane macromers, and combinations thereof.

24. The lens of claim 17 wherein at least about 30 weight % of said silicone components comprise silicone containing compounds free from branching trimethylsiloxy groups.

25. The lens of claim 17 wherein at least about 60 weight % of said silicone components comprise silicone containing compounds free from branching trimethylsiloxy groups.
Contact Lens Description
FIELD OF THE INVENTION

This invention relates to soft contact lenses displaying superior comfort when worn on eye. In particular, the invention relates to soft contact lenses displaying a unique combination of properties which provide superior on eye comfort.

BACKGROUND OF THE INVENTION

Soft contact lenses have been available since the 1980s. Currently there are two types of soft contact lenses. “Conventional” lenses are made from hydrophilic polymers such as poly(2-hydroxyethyl methacrylate) (PHEMA) and copolymers of N-vinyl pyrrolidone and methyl methacrylate. These contact lenses have relatively low permeability to oxygen (typically below 8-30 barrers), but high water content (typically in excess of 35%). Examples of a conventional soft contact lens include Acuvue.RTM. and Acuvue2.RTM. brand contact lenses, both of which are considered as among the most comfortable soft contact lenses commercially available. However, many lens wearers cannot comfortably wear conventional lenses for a full day (up to nine hours or more).

Contact lens wearers commonly report symptoms of dryness and discomfort while wearing contact lenses. These symptoms can be exacerbated in environments prone to low relative humidity, such as pressurized airline cabins, home or office environments that use forced-air heating or air-conditioning systems, as well as locales and environments subject to low ambient humidity. The relative humidity in commercial airlines commonly ranges from as low as 5% to under 40%, with mean values averaging between 14-19%.

Silicone hydrogel contact lenses contain silicone in the lens polymer. Silicone increases the lens’s oxygen permeability, which contributes to the lenses ability to be worn for longer periods of continuous wear. However, commercially available silicone hydrogel contact lenses are perceived by many lens wearers to be less comfortable than conventional contact lenses. Accordingly, there remains a need in the industry for a contact lens which can be worn comfortably for a full day of wear, even in low humidity environments.

SUMMARY OF THE INVENTION

The present invention relates to soft contact lenses having an overall comfort preference of at least about 2 to 1 as compared to an Acuvue.RTM. contact lens and measured after one week of daily wear.

The invention also relates to soft contact lenses having an overall comfort preference of at least about 2 to 1 as compared to an Acuvue2.RTM. contact lens and measured after one week of daily wear.

The invention further relates to soft contact lenses having a modulus of less than about 100 psi, oxygen transmissibility of at least about 80 barrers/mm and a dynamic coefficient of friction of less than about 0.01 when measured at a sliding speed of 10 cm/second, provided however, said contact lens is not coated with polyacrylic acid or poly(N,N-dimethylacrylamide).

DESCRIPTION OF THE FIGURES

FIG. 1 contains two photographs of the right eye of a clinical trial patient wearing spectacle lenses for one month.

FIG. 2 contains two photographs of the right eye of a clinical trial patient wearing the contact lenses of Example 5 for one month of daily wear.

FIG. 3 contains two photographs of the right eye of a clinical trial patient wearing Focus Night and Day.RTM. brand contact lenses for one month of daily wear.

FIG. 4 contains two photographs of the right eye of a clinical trial patient wearing Acuvue.RTM.2 brand contact lenses for one month of daily wear.

FIG. 5 is a graph comparing the limbal redness observed in patients wearing spectacle lenses, the contact lenses of Example 5, Focus Night and Day.RTM. brand contact lenses and Acuvue.RTM.2 brand contact lenses.

FIG. 6 is a graph comparing lid irritation observed in patients wearing spectacle lenses, the contact lenses of Example 5, Focus Night and Day.RTM. brand contact lenses and Acuvue.RTM.2 brand contact lenses.

FIG. 7 is a graph comparing the overall redness observed in patients wearing spectacle lenses, the contact lenses of Example 5, Focus Night and Day.RTM. brand contact lenses and Acuvue.RTM.2 brand contact lenses.

DETAILED DESCRIPTION OF THE INVENTION

It has been surprisingly found that contact lenses having a unique balance of properties display superior comfort compared to presently available soft contact lenses. The contact lenses of the present invention display superior overall comfort throughout wear, and at the end of the day. The lenses of the present invention were found, in clinical trials to be significantly more comfortable than Acuvue.RTM. or Acuvue.RTM.2 brand contact lenses, both of which are recognized in the industry as lenses which are among the most comfortable commercially available lenses. By significant, we mean a preference rating of at least 2 to 1 in a double masked, clinical trial with at least about 20 patients completing the trial and wearing lenses for at least 8 hours per day for at least one week. End of day comfort data was collected at least 8 hours after lens insertion. The questionnaires allowed participants the following choices: preferred the test lens, preferred the control lens, preferred both lenses or preferred neither lens. Ratings were generated using all responses indicating a preference between the lenses. Acuvue2.RTM. and Acuvue.RTM. brand contact lenses are soft hydrogel contact lenses made from etafilcon A and commercially available from Johnson & Johnson Vision Care, Inc.

Lenses of the present invention were also found to provide improved comfort in low humidity environments, generally under 40% relative humidity, such as airline cabins, heated and air conditioned buildings and the like.

It has been surprisingly found that lenses that have a modulus of less than about 140 psi, an oxygen transmissibility, Dk/t, of at least about 70 barrers/mm and a dynamic coefficient of friction (”COF”) of less than about 0.01, display superior comfort. Low modulus provides a soft and flexible lens. High oxygen transmissibility provides sufficient levels of oxygen to the cornea to prevent redness and promote corneal health, and a low dynamic COF provides the lens with a lubricious, silky feel.

Preferably the Dk/t is at least about 80 barrers/mm, in some embodiments at least about 90, and for contact lenses which are intended to be worn continuously for two weeks or more, preferably at least about 100 barrers/mm. In some embodiments, Dk/t of at least about 140 barrer/mm may be desirable.

Preferably the modulus is less than about 120 psi, more preferably less than about 100 psi, and in some embodiments between about 40 and 100 psi.

Additionally contact lenses of the present invention may have water contents of at least about 30%, and preferably between about. 30 and about 50%. The contact lenses of the present invention may also display advancing contact angles of less than about 80.degree. and preferably less than about 70.degree. as measured using a Wilhelmy dynamic contact angle balance.

Suitable components for producing soft contact lenses having a variety of properties are known in the art. The combination of components to provide the novel combination of properties disclosed in the present invention will now be described.

The oxygen transmissibility may be imparted to the lens formulation by including at least one silicone containing component in the lens formulation. Suitable silicone containing components include silicone containing monomers, prepolymer and/or macromers.

The term “monomer” used herein refers to lower molecular weight compounds that can be polymerized to higher molecular weight compounds, polymers, macromers, or prepolymers. The term “macromer” as used herein refers to a high molecular weight polymerizable compound. Prepolymers are partially polymerized monomers or monomers which are capable of further polymerization.

A “silicone-containing monomer” is one that contains at least two [--Si--O--] repeating units in a monomer, macromer or prepolymer. Preferably, the total Si and attached O are present in the silicone-containing monomer in an amount greater than 20 weight percent, and more preferably greater than 30 weight percent of the total molecular weight of the silicone-containing monomer. Useful silicone-containing components preferably comprise polymerizable functional groups such as acrylate, methacrylate, acrylamide, methacrylamide, N-vinyl lactam, N-vinylamide, and styryl functional groups. Examples of silicone-containing components which are useful in this invention may be found in U.S. Pat. Nos. 3,808,178; 4,120,570; 4,136,250; 4,153,641; 4,740,533; 5,034,461 and 5,070,215, and EP080539. All of the patents cited herein are hereby incorporated in their entireties by reference. These references disclose many examples of olefinic silicone-containing components.

While almost any silicone containing component may be included to increase the Dk of the resulting lens, in order to provide the lenses of the present invention with the desired modulus, the majority of the mass fraction of the silicone components used in the lens formulation should contain only one polymerizable functional group (”monofunctional silicone containing component”). To insure the desired balance of oxygen transmissibility and modulus it is preferred that all components having more than one polymerizable functional groups (”multifunctional components”) make up no more than 10 mmol/100 g of the reactive components, and preferably no more than 7 mmol/100 g of the reactive components. Suitable monofunctional silicone containing components include polysiloxanylalkyl(meth)acrylic monomers of Formula I:

##STR00001## wherein: R denotes H or lower alkyl; X denotes O or NR.sup.4; each R.sup.4 independently denotes hydrogen or methyl, each R.sup.1-R.sup.3 independently denotes a lower alkyl radical or a phenyl radical, and n is 1 or 3 to 10. Mono-functional polydimethylsiloxanes (mPDMS) may also be used. Suitable mPDMS compounds include Structure II:

##STR00002## where b=0 to 100, where it is understood that b is a distribution having a mode equal to a stated value, preferably 4 to 16, more preferably 8 to 10; R.sub.58 is a monovalent group containing at least one ethylenically unsaturated moiety, preferably a monovalent group containing a styryl, vinyl, or methacrylate moiety, more preferably a methacrylate moiety; each R.sub.59 is independently a monovalent alkyl, or aryl group, which may be further substituted with alcohol, amine, ketone, carboxylic acid or ether groups, preferably unsubstituted monovalent alkyl or aryl groups, more preferably methyl; R.sub.60 is a monovalent alkyl, or aryl group, which may be further substituted with alcohol, amine, ketone, carboxylic acid or ether groups, preferably unsubstituted monovalent alkyl or aryl groups, preferably a C.sub.1-10 aliphatic or aromatic group which may include hetero atoms, more preferably C.sub.3-8alkyl groups, most preferably butyl; and R.sub.61 is independently alkyl or aromatic, preferably ethyl, methyl, benzyl, phenyl, or a monovalent sloganeer chain comprising from 1 to 100 repeating Si–O units. Examples of suitable mPDMS compounds include 3-methacryloxy-2-hydroxypropyloxy)propylbis(trimethylsiloxy)methylsilane, monomethacryloxypropyl terminated mono-n-butyl terminated polydimethylsiloxane., methacryloxypropylpentamethyl disiloxane, combinations thereof and the like.

Examples of polysiloxanylalkyl (meth)acrylic monomers include methacryloxypropyl tris(trimethylsiloxy) silane, pentamethyldisiloxanyl methylmethacrylate, and methyldi(trimethylsiloxy)methacryloxymethyl silane. Methacryloxypropyl tris(trimethylsiloxy)silane is the most preferred.

In some embodiments monofunctional polydimethylsiloxanes may be preferred, as they lower not only modulus, but also tan .delta., while bulky silicones, such as those containing at least one branching trimethylsiloxy group will increase tan 67. Accordingly, at least about 30 and preferably at least about 60 weight % of all the silicone components should be non-bulky silicone containing compounds such as polydimethylsiloxanes.

Desirably, silicone hydrogels made according to the invention comprise at least about 20 and preferably between about 20 and 70% wt silicone containing components based on total weight of reactive monomer components from which the polymer is made.

In addition to the monofunctional silicone containing components, multifunctional silicone containing components and/or bulky silicone containing compounds may also be included in amounts which do not impart an undesirably high modulus and/or tan .delta..

One class of silicone-containing components is a poly(organosiloxane) prepolymer represented by formula III:

##STR00003## wherein each A independently denotes an activated unsaturated group, such as an ester or amide of an acrylic or a methacrylic acid or an alkyl or aryl group (providing that at least one A comprises an activated unsaturated group capable of undergoing radical polymerization); each of R.sup.5, R.sup.6, R.sup.7 and R.sup.8 are independently selected from the group consisting of a monovalent hydrocarbon radical or a halogen substituted monovalent hydrocarbon radical having 1 to 18 carbon atoms which may have ether linkages between carbon atoms; R.sup.9 denotes a divalent hydrocarbon radical having from 1 to 22 carbon atoms, and m is 0 or an integer greater than or equal to 1, and preferable 5 to 400, and more preferably 10 to 300. One specific example is .alpha., .omega.-bismethacryloxypropyl polydimethylsiloxane.

Another useful class of silicone containing components includes silicone-containing vinyl carbonate or vinyl carbamate monomers of the following formula:

##STR00004## wherein: Y denotes O, S. or NH; R.sup.Si denotes a silicone-containing organic radical; R denotes hydrogen or methyl; d is 1, 2, 3 or 4; and q is 0 or 1. Suitable silicone-containing organic radicals R.sup.Si include the following: –(CH.sub.2).sub.q.Si[(CH.sub.2).sub.sCH.sub.3].sub.3 –(CH.sub.2).sub.q.Si[OSi((CH.sub.2).sub.sCH.sub.3).sub.3].sub.3

##STR00005## wherein: Q denotes

##STR00006##

Wherein p is 1 to 6; R.sup.10 denotes an alkyl radical or a fluoroalkyl radical having 1 to 6 carbon atoms; e is 0 to 200; q’ is 1, 2, 3 or 4; and s is 0, 1, 2, 3, 4 or 5.

The silicone-containing vinyl carbonate or vinyl carbamate monomers specifically include: 1,3-bis[4-(vinyloxycarbonyloxy)but-1-yl]tetramethyl-disiloxane; 3-(vinyloxycarbonylthio) propyl-[tris (trimethylsiloxy)silane]; 3-[tris(trimethylsiloxy)silyl] propyl allyl carbamate; 3-[tris(trimethylsiloxy)silyl] propyl vinyl carbamate; trimethylsilylethyl vinyl carbonate; trimethylsilylmethyl vinyl carbonate, and

##STR00007##

Another class of silicone-containing components includes polyurethane macromers of the following formulae: (*D*A*D*G).sub.a*D*D*E.sup.1; E(*D*G*D*A).sub.a*D*G*D*E.sup.1 or; E(*D*A*D*G).sub.a*D*A*D*E.sup.1 Formulae IV-VI wherein:

D denotes an alkyl diradical, an alkyl cycloalkyl diradical, a cycloalkyl diradical, an aryl diradical or an alkylaryl diradical having 6 to 30 carbon atoms,

G denotes an alkyl diradical, a cycloalkyl diradical, an alkyl cycloalkyl diradical, an aryl diradical or an alkylaryl diradical having 1 to 40 carbon atoms and which may contain ether, thio or amine linkages in the main chain; * denotes a urethane or ureido linkage; .sub.a is at least 1;

A denotes a divalent polymeric radical of formula:

##STR00008## R.sup.11 independently denotes an alkyl or fluoro-substituted alkyl group having 1 to 0 carbon atoms which may contain ether linkages between carbon atoms; y is at least 1; and p provides a moiety weight of 400 to 10,000; each of E and E.sup.1 independently denotes a polymerizable unsaturated organic radical represented by formula:

##STR00009## wherein: R.sup.12 is hydrogen or methyl; R.sup.13 is hydrogen, an alkyl radical having 1 to 6 carbon atoms, or a –CO–Y–R.sup.15 radical wherein Y is –O–, Y–S– or –NH–; R.sup.14 is a divalent radical having 1 to 12 carbon atoms; X denotes –CO– or –OCO–; Z denotes –O– or –NH–; Ar denotes an aromatic radical having 6 to 30 carbon atoms; w is 0 to 6; x is 0 or 1; y is 0 or 1; and z is 0 or 1.

A preferred silicone-containing component is a polyurethane macromer represented by the following formula:

##STR00010## wherein R.sup.16 is a diradical of a disocyanate after removal of the isocyanate group, such as the diradical of isophorone diisocyanate. Another suitable silicone containing macromer is compound of formula X (in which x+y is a number in the range of 10 to 30) formed by the reaction of fluoroether, hydroxy-terminated polydimethylsiloxane, isophorone diisocyanate and isocyanatoethylmethacrylate.

##STR00011##

Other silicone-containing components suitable for use in this invention include those described is WO 96/31792 such as macromers containing polysiloxane, polyalkylene ether, diisocyanate, polyfluorinated hydrocarbon, polyfluorinated ether and polysaccharide groups. U.S. Pat. Nos. 5,321,108; 5,387,662 and 5,539,016 describe polysiloxanes with a polar fluorinated graft or side group having a hydrogen atom attached to a terminal difluoro-substituted carbon atom. US 2002/0016383 describe hydrophilic siloxanyl methacrylates containing ether and siloxanyl linkanges and crosslinkable monomers containing polyether and polysiloxanyl groups. Any of the foregoing polysiloxanes can also be used as the silicone containing component in this invention.

Hydrophilic monomers are also included in the reactive components used to make the contact lenses of the present invention. The hydrophilic monomers used to make the contact lenses of this invention can be any of the known hydrophilic monomers disclosed in the prior art to make hydrogels.

The preferred hydrophilic monomers used to make the polymer of this invention may be either acrylic- or vinyl-containing. Such hydrophilic monomers may themselves be used as crosslinking agents, however, where hydrophilic monomers having more than one polymerizable functional group are used, their concentration should be limited as discussed above to provide a contact lens having the desired modulus. The term “vinyl-type” or “vinyl-containing” monomers refer to monomers containing the vinyl grouping (–CH.dbd.CH.sub.2) and are generally highly reactive. Such hydrophilic vinyl-containing monomers are known to polymerize relatively easily. “Acrylic-type” or “acrylic-containing” monomers are those monomers containing the acrylic group: (CH.sub.2.dbd.CRCOX) wherein R is H or CH.sub.3, and X is O or N, which are also known to polymerize readily, such as N,N-dimethyl acrylamide (DMA), 2-hydroxyethyl methacrylate (HEMA), glycerol methacrylate, 2-hydroxyethyl methacrylamide, polyethyleneglycol monomethacrylate, methacrylic acid and acrylic acid.

Hydrophilic vinyl-containing monomers which may be incorporated into the silicone hydrogels of the present invention include monomers such as N-vinyl amides, N-vinyl lactams (e.g. NVP), N-vinyl-N-methyl acetamide, N-vinyl-N-ethyl acetamide, N-vinyl-N-ethyl formamide, N-vinyl formamide, with NVP being preferred.

Other hydrophilic monomers that can be employed in the invention include polyoxyethylene polyols having one or more of the terminal hydroxyl groups replaced with a functional group containing a polymerizable double bond. Examples include polyethylene glycol, ethoxylated alkyl glucoside, and ethoxylated bisphenol A reacted with one or more molar equivalents of an end-capping group such as isocyanatoethyl methacrylate (”IEM”), methacrylic anhydride, methacryloyl chloride, vinylbenzoyl chloride, or the like, to produce a polyethylene polyol having one or more terminal polymerizable olefinic groups bonded to the polyethylene polyol through linking moieties such as carbamate or ester groups.

Still further examples are the hydrophilic vinyl carbonate or vinyl carbamate monomers disclosed in U.S. Pat. No. 5,070,215, and the hydrophilic oxazolone monomers disclosed in U.S. Pat. No. 4,910,277. Other suitable hydrophilic monomers will be apparent to one skilled in the art.

More preferred hydrophilic monomers which may be incorporated into the polymer of the present invention include hydrophilic monomers such as DMA, HEMA, glycerol methacrylate, 2-hydroxyethyl methacrylamide, NVP, N-vinyl-N-methyl acrylamide, polyethyleneglycol monomethacrylate, methacrylic acid and acrylic acid with DMA being the most preferred.

The hydrophilic monomers may be present in a wide range of amounts, depending upon the specific balance of properties desired. Amounts of hydrophilic monomer up to about 50 and preferably between about 5 and about 50 weight %, based upon all components in the reactive components are acceptable. For example, in one embodiment lenses of the present invention comprise a water content of at least about 30%, and in another embodiment between about 30 and about 50%. For these embodiments, the hydrophilic monomer may be included in amounts between about 20 and about 50 weight %.

The lenses of the present invention have a dynamic COF less than 0.01. The dynamic COF may be imparted to the contact lens by incorporating a lubricious polymer into the reactive mixture from which the lens will be made, or by coating a lens with a lubricious polymer. Suitable lubricious polymers have a weight average molecular weight of at least about 50,000 Daltons, and in some embodiments greater than about 100,000 Daltons. The molecular weight may be determined via gel permeation chromatography (GPC) using a ViscoGEL GMPWXL Column with a 20/80 methanol/water ratio with a flow rate 1.0 ml/min. at 30.degree. C.

Suitable lubricious polymers will also possess, when polymerized and crosslinked to minor amount, a water content of at least about 70%, preferably at least about 80%. For lubricious polymers which are free radical reactive, a “minor amount” of crosslinking may be effected by polymerizing the monomer(s) from which the polymer is formed with a small amount (such as about 7.5 mmol/100 gram of polymer) of crosslinker (for example, EGDMA). Methods for forming crosslinked polymers which are not free radical reactive will be apparent to those of skill in the art from the disclosure contained herein.

Alternatively, the suitability of a polymer for use as a lubricious polymer may be determined by mixing 10 wt % of the monomer from which the polymer is formed in water at room temperature. Monomers that are soluble under these conditions may be used to form lubricious polymers for use in the contact lenses of the present invention. Specific examples of lubricious polymers include high molecular weight hydrophilic polymers of polyamides, polylactones, polyimides, polylactams and functionalized polyamides, polylactones, polyimides, polylactams, such as DMA functionalized by copolymerizing DMA with a lesser molar amount of a hydroxyl-functional monomer such as HEMA, and then reacting the hydroxyl groups of the resulting copolymer with materials containing radical polymerizable groups, such as isocyanatoethylmethacrylate or methacryloyl chloride. Hydrophilic polymers or prepolymers made from DMA or n-vinyl pyrrolidone with glycidyl methacrylate may also be used. The glycidyl methacrylate ring can be opened to give a diol which may be used in conjunction with other hydrophilic prepolymers in a mixed system. Specific examples of lubricious polymers include but are not limited to poly-N-vinyl pyrrolidone, poly(N-vinyl-N-methylacetamide), poly-N-vinyl-2-piperidone, poly-N-vinyl-2-caprolactam, poly-N-vinyl-3-methyl-2-caprolactam, poly-N-vinyl-3-methyl-2-piperidone, poly-N-vinyl-4-methyl-2-piperidone, poly-N-vinyl-4-methyl-2-caprolactam, poly-N-vinyl-3-ethyl-2-pyrrolidone, and poly-N-vinyl-4,5-dimethyl-2-pyrrolidone, polyvinylimidazole, poly-N-N-dimethylacrylamide, polyvinyl alcohol, polyethylene oxide, poly 2 ethyl oxazoline, heparin polysaccharides, polysaccharides, mixtures and copolymers (including block or random, branched, multichain, comb-shaped or star shaped) thereof where poly-N-vinylpyrrolidone (PVP), poly(N-vinyl-N-methylacetamide) (PVMA) are particularly preferred. Copolymers might also be used such as graft copolymers of PVP or amphiphilic copolymers having hydrophilic and hydrophobic blocks such as those disclosed in U.S. Ser. No. 10/954,560. The lubricious polymer may be incorporated into the lens polymer without chemical bonding, such as is disclosed in US 2003/162,862 and US 2003/125,498 or may be copolymerized into the lens matrix or coated onto the contact lens, by any known method such as premold spin casting, as disclosed, for example, in US 2003/052,424, grafting, soaking the lens in a polymeric solution as disclosed in US 2002/006,521 and U.S. Pat. No. 6,478,423, and the like.

When the lubricious polymer is incorporated into the lens polymer, the lubricious polymer may also comprise polyacrylic acid. However, when the lubricious polymer is coated onto the lens, the lubricious polymer is not polyacrylic acid or poly(N,N-dimethylacrylamide).

Alternatively, the lubricious polymer may be a reactive polymer have a molecular weight as low as 2000. Suitable low molecular weight polymers are disclosed in U.S. Ser. No. 10/954559.

The lubricious polymer is incorporated into or onto the lens in amounts sufficient to provide the desired COF. When the lubricious polymer is incorporated into the lens, it may be included in the reaction mixture in amounts between about 1 to about 15 weight percent, more preferably about 3 to about 15 percent, most preferably about 5 to about 12 percent, all based upon the total of all reactive components.

When the lubricious polymer is coated onto the lens any amount which is sufficient to coat the surface of the lens and provide the desired COF may be used (”coating effective amount”). Generally, the amount of lubricious polymer used may be about 0.001 to about 100, preferably about 0.01 to about 50 and more preferably about 0.01 to about 10 weight percent of the coating solution.

Other monomers that can be present in the reaction mixture used to form the contact lenses of this invention include compatibilizing components, such as those disclosed in US 2003/162,862 and US 2003/2003/125,498, ultra-violet absorbing compounds, medicinal agents, antimicrobial compounds, copolymerizable and nonpolymerizable dyes, release agents, reactive tints, pigments, combinations thereof and the like.

A polymerization catalyst is preferably included in the reaction mixture. The polymerization initiators includes compounds such as lauryl peroxide, benzoyl peroxide, isopropyl percarbonate, azobisisobutyronitrile, and the like, that generate free radicals at moderately elevated temperatures, and photoinitiator systems such as aromatic alpha-hydroxy ketones, alkoxyoxybenzoins, acetophenones, acylphosphine oxides, bisacylphosphine oxides, and a tertiary amine plus a diketone, mixtures thereof and the like. Illustrative examples of photoinitiators are 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1 -one, bis(2,6-dimethoxybenzoyl)-2,4-4-trimethylpentyl phosphine oxide (DMBAPO), bis(2,4,6-trimethylbenzoyl)-phenyl phosphineoxide (Irgacure 819), 2,4,6-trimethylbenzyldiphenyl phosphine oxide and 2,4,6-trimethylbenzoyl diphenylphosphine oxide, benzoin methyl ester and a combination of camphorquinone and ethyl 4-(N,N-dimethylamino)benzoate. Commercially available visible light initiator systems include Irgacure 819, Irgacure 1700, Irgacure 1800, Irgacure 819, Irgacure 1850 (all from Ciba Specialty Chemicals) and Lucirin TPO initiator (available from BASF). Commercially available UV photoinitiators include Darocur 1173 and Darocur 2959 (Ciba Specialty Chemicals). These and other photoinitators which may be used are disclosed in Volume III, Photoinitiators for Free Radical Cationic & Anionic Photopolymerization, 2.sup.nd Edition by J. V. Crivello & K. Dietliker; edited by G. Bradley; John Wiley and Sons; New York; 1998. The initiator is used in the reaction mixture in effective amounts to initiate photopolymerization of the reaction mixture, e.g., from about 0.1 to about 2 parts by weight per 100 parts of reactive monomer. Polymerization of the reaction mixture can be initiated using the appropriate choice of heat or visible or ultraviolet light or other means depending on the polymerization initiator used. Alternatively, initiation can be conducted without a photoinitiator using, for example, e-beam. However, when a photoinitiator is used, the preferred initiators are bisacylphosphine oxides, such as bis(2,4,6-trimethylbenzoyl)-phenyl phosphine oxide (Irgacure 819.RTM.) or a combination of 1-hydroxycyclohexyl phenyl ketone and bis(2,6-dimethoxybenzoyl)-2,4-4-trimethylpentyl phosphine oxide (DMBAPO) ,and the preferred method of polymerization initiation is visible light. The most preferred is bis(2,4,6-trimethylbenzoyl)-phenyl phosphine oxide (Irgacure 819.RTM.).

The reactive components (silicone containing component, hydrophilic monomers, lubricious polymers, and other components which are reacted to form the lens) are mixed together either with or without a diluent to form the reaction mixture. The diluent is selected to solubilize the reactive components. Suitable diluents include include those which possess both a hydrophilic and a hydrophobic nature. It has been found that the hydrophilic nature may be characterized by hydrogen donating ability, using Kamlet alpha values (also referred to as alpha values). The hydrophobic nature of the diluent may be characterized by the Hansen solubility parameter .delta.p. Suitable diluents for the present invention are good hydrogen bond donors and polar. As used herein a “good” hydrogen bond donor, will donate hydrogen at least as readily as 3-methyl-3-pentanol. For certain diluents it is possible to measure the hydrogen bond donating ability by measuring the Kamlet alpha value (or as used herein “alpha value”). Suitable alpha values include those between about 0.05 and about 1 and preferably between about 0.1 and about 0.9.

The diluents useful in the present invention should also be relatively non-polar. The selected diluent should have a polarity sufficiently low to solubilize the non-polar components in the reactive mixture at reaction conditions. One way to characterize the polarity of the diluents of the present invention is via the Hansen solubility parameter, .delta.p. In certain embodiments, the .delta.p is less than about 10, and preferably less than about 6. Suitable diluents are further disclosed in U.S. Ser. No. 60/452898 and U.S. Pat. No. 6,020,445. Classes of suitable diluents include, without limitation, alcohols having 2 to 20 carbons, amides having 10 to 20 carbon atoms derived from primary amines and carboxylic acids having 8 to 20 carbon atoms. In some embodiments, primary and tertiary alcohols are preferred. Preferred classes include alcohols having 5 to 20 carbons and carboxylic acids having 10 to 20 carbon atoms.

Preferred diluents include 3,7-dimethyl-3-octanol, 1-dodecanol, 1-decanol, 1 -octanol, 1 -pentanol, 1 -hexanol, 2-hexanol, 2-octanol, 3-methyl-3-pentanol, 2-pentanol, t-amyl alcohol, tert-butanol, 2-butanol, 1-butanol, 2-methyl-2-pentanol, 2-ethyl-1-butanol, ethanol, 3,3-dimethyl-2-butanol, 2-octyl-1 -dodecanol, decanoic acid, octanoic acid, dodecanoic acid, mixtures thereof and the like.

More preferred diluents include 3,7-dimethyl-3-octanol, 1 -dodecanol, 1-decanol, 1-octanol, 1-pentanol, 1-hexanol, 2-hexanol, 2-octanol, 1-dodecanol, 3-methyl-3-pentanol, 1-pentanol, 2-pentanol, t-amyl alcohol, tert-butanol, 2-butanol, 1 -butanol, 2-methyl-2-pentanol, 2-ethyl-1-butanol, 3,3-dimethyl-2-butanol, 2-octyl-1 -dodecanol, mixtures thereof and the like.

Various processes are known for molding the reaction mixture in the production of contact lenses, including spincasting and static casting. Spincasting methods are disclosed in U.S. Pat. Nos. 3,408,429 and 3,660,545, and static casting methods are disclosed in U.S. Pat. Nos. 4,113,224 and 4,197,266. The preferred method for producing contact lenses comprising the polymer of this invention is by the direct molding of the silicone hydrogels, which is economical, and enables precise control over the final shape of the hydrated lens. For this method, the reaction mixture is placed in a mold having the shape of the final desired silicone hydrogel, i.e. water-swollen polymer, and the reaction mixture is subjected to conditions whereby the monomers polymerize, to thereby produce a polymer in the approximate shape of the final desired product. Then, this polymer mixture is optionally treated with a solvent and then water, producing a silicone hydrogel having a final size and shape which are quite similar to the size and shape of the original molded polymer article. This method can be used to form contact lenses and is further described in U.S. Pat. Nos. 4,495,313; 4,680,336; 4,889,664; and 5,039,459, incorporated herein by reference. After producing the silicone hydrogel, the lens be may be coated with a hydrophilic coating. Some methods of adding hydrophilic coatings to a lens have been disclosed in the prior art, including U.S. Pat. Nos. 3,854,982, 3,916,033, 4,920,184, 5,002,794, 5,779,943, 6,087,415; WO 91/04283, and EPO 93/810,399.

The non-limiting examples below further describe this invention.

Test Methods

The dynamic contact angle or DCA, was measured at 23.degree. C., with borate buffered saline, using a Wilhelmy balance. The wetting force between the lens surface and borate buffered saline is measured using a Wilhelmy microbalance while the sample strip cut from the center portion of the lens is being immersed into the saline at a rate of 100 microns/sec . The following equation is used F=2.gamma.p cos .theta. or .theta.=cos.sup.-1(F/2.gamma.p) where F is the wetting force, .gamma. is the surface tension of the probe liquid, p is the perimeter of the sample at the meniscus and .theta. is the contact angle. Typically, two contact angles are obtained from a dynamic wetting experiment–advancing contact angle and receding contact angle. Advancing contact angle is obtained from the portion of the wetting experiment where the sample is being immersed into the probe liquid, and these are the values reported herein. At least four lenses of each composition are measured and the average is reported.

Oxygen permeability was determined by the polarographic method generally described in ISO 9913-1: 1996(E), but with the following variations. The measurement is conducted at an environment containing 2.1% oxygen. This environment is created by equipping the test chamber with nitrogen and air inputs set at the appropriate ratio, for example 1800 ml/min of nitrogen and 200 ml/min of air. The t/Dk is calculated using the adjusted P.sub.O2. Borate buffered saline was used. The dark current was measured by using a pure humidified nitrogen environment instead of applying MMA lenses. The lenses were not blotted before measuring. Four lenses were stacked instead of using lenses of varied thickness. A curved sensor was used in place of a flat sensor. The resulting Dk value is reported in barrers (1 barrer=10.sup.-10 (cm.sup.3 of gas.times.cm.sup.2)/(cm.sup.3 of polymer.times.sec.times.cm Hg). Oxygen transmissibility is oxygen permeability divided by the thickness of the lens. Lens thickness is measured using a micrometer, such as a Reider guage at the center of a hydrated lens, using a flat anvil.

The water content was measured as follows: lenses to be tested were allowed to sit in packing solution for 24 hours. Each of three test lens were removed from packing solution using a sponge tipped swab and placed on blotting wipes which have been dampened with packing solution Both sides of the lens were contacted with the wipe. Using tweezers, the test lens were placed in a weighing pan and weighed. The two more sets of samples were prepared and weighed as above. The pan was weighed three times and the average is the wet weight.

The dry weight was measured by placing the sample pans in a vacuum oven which has been preheated to 60.degree. C. for 30 minutes. Vacuum was applied until at least 0.4 inches Hg is attained. The vacuum valve and pump were turned off and the lenses were dried for four hours. The purge valve was opened and the oven was allowed reach atmospheric pressure. The pans were removed and weighed. The water content was calculated as follows: Wet weight=combined wet weight of pan and lenses-weight of weighing pan Dry weight=combined dry weight of pan and lens-weight of weighing pan

.times..times..times..times..times..times..times..times..times..times..tim- es. ##EQU00001## The average and standard deviation of the water content are calculated for the samples are reported.

Modulus was measured by using the crosshead of a constant rate of movement type tensile testing machine equipped with a load cell that is lowered to the initial gauge height. A suitable testing machine includes an Instron model 1122. A dog-bone shaped sample having a 0.522 inch length, 0.276 inch “ear” width and 0.213 inch “neck” width was loaded into the grips and elongated at a constant rate of strain of 2 in/min. until it broke. The initial gauge length of the sample (Lo) and sample length at break (Lf) were measured. Twelve specimens (either -0.05 or -1.00D) of each composition were measured and the average is reported. Tensile modulus was measured at the initial linear portion of the stress/strain curve. Percent elongation is=[(Lf-Lo)/Lo].times.100.

The dynamic coefficient of friction of the contact lens was measured using a Micro-Tribometer, Model UMT-2 unit, with a pin-on-disk sample mount. The contact lens sample was removed from its packing solution and placed on the tip of the “pin” with the center of the lens on the pin tip and pressed against a highly polished stainless steel disk moving at a constant speed of either 10 or 15 cm/sec. Loads of 3, 5, 10 and 20 g were used. The duration at each load was 25 seconds and all measurements were taken at ambient temperature. The resistant frictional force was measured and was used to calculate the coefficient of friction using the following formula: =(F-f’)/N, where

=coefficient of friction

F=measured frictional force, f+f’

f=actual frictional force

f’=experimental artifacts due lens deformation, such as dehydration and interfacial surface tension forces, elasticity, etc.

N=normal load

Seven lenses were tested for each lens type. The coefficient of friction were averaged and reported

In the examples, the following abbreviations are used.

TABLE-US-00001 SiGMA 2-propenoic acid, 2-methyl-,2-hydroxy-3-[3-[1,3,3,3- tetramethyl-1-[(trimethylsilyl)oxy]disiloxanyl] propoxy]propyl ester DAROCUR 1173 2-hydroxy-2-methyl-1-phenyl propane-1-one DMA N,N-dimethylacrylamide HEMA 2-hydroxyethyl methacrylate mPDMS 800-1000 MW (M.sub.n) monomethacryloxypropyl terminated mono-n-butyl terminated polydimethylsiloxane MAA methacrylic acid Norbloc 2-(2′-hydroxy-5-methacrylyloxyethylphenyl)-2H- benzotriazole CGI 1850 1:1 (wgt) blend of 1-hydroxycyclohexyl phenyl ketone and bis(2,6-dimethoxybenzoyl)-2,4-4-trimethylpentyl phosphine oxide PVP poly(N-vinyl pyrrolidone) (K value 90) Blue HEMA the reaction product of Reactive Blue 4 and HEMA, as described in Example 4 of U.S. Pat. No. 5,944,853 IPA isopropyl alcohol D3O 3,7-dimethyl-3-octanol TEGDMA tetraethyleneglycol dimethacrylate TRIS 3-methacryloxypropyltris(trimethylsiloxy)silane PAA poly(acrylic acid) CGI 819 bis(2,4,6-trimethylbenzoyl)-phenylphosphineoxide

EXAMPLE 1

The reaction components and diluent (D30) listed in Table 1 were mixed together until all components were dissolved. The 5 reactive components are reported as weight percent of all reactive components and the diluent is weight percent of final reaction mixture. The reaction mixture was placed into thermoplastic contact lens molds (front molds made from Zeonor.RTM., back molds made from polypropylene) and irradiated at 60.degree. C. with 0.5 mW/cm.sup.2, followed by 1 mW/cm.sup.2 then 3 mW/ cm.sup.2 visible light using Philips TL 20W/03T fluorescent bulbs. The molds were opened and lenses were extracted five times with IPA at ambient temperature for about 2 hours per cycle to remove residual diluent and monomers, placed into borate-buffered saline solution. The physical properties of the lenses (Dk, water content, advancing dynamic contact angle, modulus, elongation and dynamic coefficient of friction) were measured and are shown in Table 3, below.

TABLE-US-00002 TABLE 1 Component Wt % SiGMA 28 PVP (K90) 7 DMA 23.5 MPDMS 31 HEMA 6 Norbloc 2 TEGDMA 1.5 Blue HEMA 0.02 CGI 1850 0.98 % Diluent* 23 Diluent D3O

EXAMPLE 2

The lenses of Example 1 were clinically evaluated against Acuvue.RTM. brand contact lenses. The clincial evaluation, was a randomized, bilateral cross-over study with 39 patients. The lenses were worn in a daily wear mode (nightly removal) for a period of one week using ReNu MultiPlus Multi-Purpose Solution. After 30 minutes and one week of wear for each leris, the patients were asked to rate the lenses for the following: dryness, initial comfort, end of day comfort, overall preference. Each attribute is rated on a visual analog questionnaire form. The form consisted of a visual analog from 0 to 50 with verbal descriptions at specific intervals to explain the scale to the subject (50=excellent, 0=very poor). Lenses, which score above 42 on the scale, are considered good to excellent. A mean difference of five units between the lens types is considered clinically significant. Table 2 shows the preference results from the clinical study.

TABLE-US-00003 TABLE 2 Ex. 1 v. Acuvue .RTM. contact Attribute lenses Overall Preference 23:6 Initial Comfort 21:3 Dryness 20:3 End of Day Comfort 18:3

TABLE-US-00004 TABLE 3 Property Ex 1 – Acuvue .RTM. contact lenses Dk (barrer) 101 21 Center thickness 0.078-0.0.087 0.011 (mm) % H2O 36-37 58 DCA (.degree.) 55-57 82 Modulus (psi) 87 37 Elongation (%) 223 120 COF (@ 10 cm/s) 0.005

EXAMPLE 3

Lenses were made from the formulation in Table 4. The preparation of the macromer used is described in US Patent application 200300052424.

Lenses were formed in using a process similar to that of Example 1, but with TOPAS.RTM. front molds and polypropylene back molds, curing under visible light at 70.degree. C. Lenses were made as above except with the application of a polyHEMA coating to the surfaces of the molds as described in Examples 10-13 of US Patent application 200300052424.

TABLE-US-00005 TABLE 4 Component Wt % Macromer 18 TRIS 14 PVP (K90) 5 DMA 26 MPDMS 28 HEMA 5 Norbloc 2 TEGDMA 1 Blue HEMA 0.02 CGI 1850 1 % Diluent* 20 Diluent D3O

The physical properties of the lenses (Dk, water content, advancing dynamic contact angle, modulus, elongation and dynamic coefficient of friction were measured and are shown in Table 6, below.

EXAMPLE 4

The lenses of Example 3 were clinically evaluated against Acuvue.RTM. brand contact lenses. The clincial evaluation, was a randomized, bilateral cross-over study with 53 patients. The lenses were worn in a daily wear mode (nightly removal) for a period of one week using SoloCare Multi-Purpose Solution. After 30 minutes and one week of wear for each lens, the patients were asked to rate the lenses for the following: dryness, initial comfort, end of day comfort, overall preference. Each attribute is rated on a visual analog questionnaire form. The form consisted of a visual analog from 0 to 50 with verbal descriptions at specific intervals to explain the scale to the subject (50=excellent, 0=very poor). Lenses, which score above 42 on the scale, are considered good to excellent. A mean difference of five units between the lens types is considered clinically significant. Table 5 shows the preference results from the clinical study.

TABLE-US-00006 TABLE 5 Ex. 3 v. Acuvue .RTM. contact Attribute lenses Overall Preference 20:10 Initial Comfort 17:10 Dryness 14:12 End of Day Comfort 16:12

TABLE-US-00007 TABLE 6 Property Ex 3 Acuvue .RTM. contact lenses Dk (barrer) 99 21 Center Thickness 0.064-0.072 0.011 (mm) % H2O 40-41 58 DCA (.degree.) 83-94 82 Modulus (psi) 75 37 Elongation (%) 281 120 COF (@ 10 cm/s) 0.024

EXAMPLE 5

Lenses were made from the formulation indicated in Table 7 in a process similar to that of Example 1.

TABLE-US-00008 TABLE 7 Component Wt % SiGMA 30 PVP (K90) 6 DMA 31 MPDMS 22 HEMA 8.5 Norbloc 1.5 EGDMA 0.8 Blue HEMA 0 CGI 819 0.2 % Diluent* 40 Diluent 29/11 blend of t- amyl alcohol and 2,500 MW PVP

The physical properties of the lenses (Dk, water content, advancing dynamic contact angle, modulus, elongation and dynamic coefficient of friction were measured and are shown in Table 9, below.

EXAMPLE 6

The lenses of Example 5 were clinically evaluated against Acuvue2.RTM. brand contact lenses. The clincial evaluation, was a double masked, bilateral cross-over study with 43 patients. The lenses were worn in a daily wear mode (nightly removal) for a period of two weeks using Complete.RTM. cleaning and disinfection system upon lens removal. After 30 minutes and two weeks of wear for each lens, the patients were asked to rate the lenses for the following: dryness, initial comfort, end of day comfort, overall preference. Each attribute is rated on a visual analog questionnaire form. The form consisted of a visual analog from 0 to 50 with verbal descriptions at specific intervals to explain the scale to the subject (50=excellent, 0=very poor). Lenses, which score above 42 on the scale, are considered good to excellent. A mean difference of five units between the lens types is considered clinically significant. Table 5 shows the preference results from the clinical study.

TABLE-US-00009 TABLE 8 Ex. 5 v. Acuvue2 .RTM. contact Attribute lenses Overall Preference 15:14 Initial Comfort 14:12 Dryness 12:8 End of Day Comfort 12:10

TABLE-US-00010 TABLE 9 Acuvue2 .RTM. contact Property Ex 5 lenses Dk (barrer) 57 21 Center thickness 0.057-0.079 0.084 (mm) % H2O 47-49 58 DCA (.degree.) 33-66 82 Modulus (psi) 66 37 Elongation (%) 258 120 COF (@ 10 cm/s) 0.006

EXAMPLE 7

The lenses of Example 1 were compared to Focus Night & Day.RTM. brand contact lenses (commercially available from Ciba Vision) in a one week, daily wear, bilateral cross-over, randomized, design study. There were 35 patients in the study. The lenses were worn in a daily wear mode (nightly removal) for a period of two weeks using ReNu MultiPlus Multi-Purpose Solution for cleaning upon lens removal. After 30 minutes and one week of wear for each lens, the patients were asked to rate the lenses for the following: dryness, initial comfort, end of day comfort, overall preference. Each attribute is rated on a visual analog questionnaire form. The form consisted of a visual analog from 0 to 50 with verbal descriptions at specific intervals to explain the scale to the subject (50=excellent, 0=very poor). Lenses, which score above 42 on the scale, are considered good to excellent. A mean difference of five units between the lens types is considered clinically significant. Table 10 shows the preference results from the clinical study. Table 11 shows a comparison of physical properties between the lens of Example 1 and the Focus Night and Day brand contact lens.

TABLE-US-00011 TABLE 10 Ex. 1 v. Focus Night and Attribute Day .RTM. contact lenses Overall Preference 25:5 Initial Comfort 25:3 Dryness 18:3 End of Day Comfort 22:5

TABLE-US-00012 TABLE 12 Focus Night and Day .RTM. Property Ex 1 contact lenses Dk (barrer) 107 140 Center thickness 0.088-0.092 NM (mm) % H2O 35-37 24 DCA (.degree.) 48-53 67 Modulus (psi) 86 238 Elongation (%) 250 178 COF (@ 10 cm/s) 0.005 0.049 NM = not measured, but nominal center thickness was reported to be 0.08

EXAMPLE 8

The lenses of Example 1 were compared to PureVision.RTM. brand contact lenses (commercially available from Bausch & Lomb) in a one month, continuous wear, contarlateral, randomized per eye study. There were 26 patients in the study. After 30 minutes and one week of wear for each lens, the patients were asked to rate the lenses for the following: dryness, initial comfort, end of day comfort, overall preference. Each attribute is rated on a visual analog questionnaire form. The form consisted of a visual analog from 0 to 50 with verbal descriptions at specific intervals to explain the scale to the subject (50=excellent, 0=very poor). Lenses, which score above 42 on the scale, are considered good to excellent. A mean difference of five units between the lens types is considered clinically significant. Table 12 shows the preference results from the clinical study. Table 13 shows a comparison of physical properties between the lens of Example 1 and the PureVision and Day brand contact lens.

TABLE-US-00013 TABLE 12 Ex. 1 v. PureVision .RTM. contact Attribute lenses Overall Preference 14:2 Initial Comfort 14:2 Dryness 11:2 End of Day Comfort 13:1

TABLE-US-00014 TABLE 13 PureVision .RTM. contact Property Ex 1 lenses Dk (barrer) 107 79 Center thickness 0.088-0.092 NM (mm) % H2O 35-37 38 DCA (.degree.) 48-53 117 Modulus (psi) 86 155 Elongation (%) 250 286 COF (@ 10 cm/s) 0.005 0.020 NM = not measured, but nominal center thickness was reported to be 0.09

EXAMPLE 9

A clinical study was conducted comparing patient response to the lenses of Example 5, Focus Night and Day.RTM. contact lenses, Acuvue.RTM.2 brand contact lenses and for redness, no contact lens wear. The lenses were worn in a daily wear modality for four weeks. The replacement interval for the Focus Night and Day.RTM. contact lenses was four weeks and the replacement interval for the lenses of Example 5 and the Acuvue.RTM.2 lenses was two weeks. Forty-eight patients who had never worn contact lenses were recruited for the study and randomly assigned to wear on of the three lenses being studied, or no lenses at all. The subjects were not informed of the brand of lens they were evaluated and did not see any lens product packaging. The study was a four cell, parallel, randomized and controlled double masked dispensing study. Optifree Express was used as the lens care solution. For all visits one investigator performed lens related assessments (such as lens fit) and removed the contact lenses (if worn by the subject being evaluated) and another performed redness and lid irritation assessments. In this way, the lens identity was masked from the investigators performing the performance evaluations. Photographs of the patients right eye in each group were taken prior to dispensing the contact lenses and after 1 month. Representative photographs are shown in FIGS. 1 through 4. In each Figure the photograph on the right was the photograph taken prior to lens wear and the photograph on the left was taken at the four month visit. Each visit was conducted at least 2 hours after the patient had woke up that day. FIG. 1 contains the photographs from a blue eyed patient who wore spectacle lenses throughout the study. As can be seen from comparing the photographs in FIG. 1, there is no significant difference in redness in the eyes of this patient.

FIG. 2 contains the photographs from a blue eyed patient who wore lenses of Example 5 throughout the study. As can be seen from comparing the photographs in FIG. 2, there is no significant difference in redness in the eyes of this patient, even after wearing contact lenses on a daily wear basis for a month.

FIG. 3 contains the photographs from a blue eyed patient who wore Focus Night and Day.RTM. contact lenses throughout the study. As can be seen from comparing the photographs in FIG. 3, and particularly the area within the circle, there is a discernable increase in general redness, which manifests itself as increased and more pronounced visible capiliaries in the conjuctiva. General redness, as shown here, may reflect irritation and/or dryness.

FIG. 4 contains the photographs from a blue eyed patient who wore Acuvue.RTM.2 brand contact lenses throughout the study. As can be seen from comparing the photographs in FIG. 4, and particularly the area within the circles, there is a discernable increase in general redness, which manifests itself as increased and more pronounced visible capiliaries in the conjuctiva (circles on the right hand side of the slides). General redness, as shown here, may reflect irritation and/or dryness. There is also an increase in limbal redness, which is shown in the picture on the right as more redness around the limbal ring (lower left circle). An increase in limbal redness may reflect less than optimum concentrations of oxygen is reaching the cornea.

Ratings for limbal redness, lid irritation and overall redness were also collected by the masked investigator, and are shown graphically in FIGS. 5 through 7, respectively. FIGS. 5-7 clearly show that the lenses of Example 5 are superior to Acuvue2 brand contact lenses in all three metrics, and superior to Focus Night and Day.RTM. contact lenses with respect to lid irritation and overall redness.

Survey information from the patients related to duration of daily lens wear and the number of hours lens wear was comfortable, was collected by an independent research organization by phone one week after the initial visit and after the replacement interview (4 weeks for Focus Night and Day.RTM. contact lenses, and two weeks for the lenses of Example 5 and Acuvue.RTM.2 contact lenses. The results of the phone survey are shown in Table 14, below.

TABLE-US-00015 TABLE 14 % reporting comfortable Lens % wore lens .gtoreq.9 hrs wear for .gtoreq.9 hrs Ex. 5 94 87 FND 91 69 AV2 90 77

EXAMPLE 10

2.02 g 1-vinyl-2-pyrrolidnone (NVP), 0.03 g of ethyleneglycol dimethacrylate (EGDMA), and 10 .mu.L of DAROCUR 1173 were combined. The blend was degassed by placing under vacuum for 30 minutes. Polymer was formed by placing 100 .mu.L of the blend into a polypropylene molds under nitrogen and curing with UV light from Phillip’s TL20W/09 bulbs for about 45 minutes. The molds were opened and polymer obtained was released into buffered saline solution at 25.degree. C. The buffered saline was replaced with fresh solution every 30 minutes for a total of three soakings. The water content of the hydrated polymer was determined and is reported in Table 15, below.

EXAMPLES 11-14

The procedure of Example 10 was repeated substituting the monomers listed in Table 15 for NVP. The results are shown in Table 15.

TABLE-US-00016 TABLE 15 Ex. # Monomer H2O % 10 1-Vinyl-2-pyrrolidnone 90.1 .+-. 0.7 11 N’N-Dimethyl acrylamide 81.4 .+-. 0.0 12 Acrylic acid 78.4 .+-. 0.2 13 N-Methyl-N-vinylacetamide 94.7 .+-. 0.4 14 1.41 g HEMA/0.61 g MAA 78.0 .+-. 0.3

1. A contact lens, comprising: a non-opaque pupil section; an iris section surrounding the pupil section; and a colored opaque intermittent pattern overlying about 20% of the iris section, wherein the colored opaque intermittent pattern comprises an outermost starburst portion comprising dots of a first shade; an outer starburst portion comprising dots of a second shade and overlapping at least a portion of the outermost starburst portion, wherein the first and second shades are different from one another; and an inner starburst portion comprising dots of a third shade and overlapping at least a portion of the outer starburst portion, wherein the overlapping of the dots of the outer starburst portion and the inner starburst portion blend together to produce a fourth shade, wherein the overlapping of the dots of the outermost starburst and the outer starburst and the overlapping of the dots of the outer starburst and the inner starburst are indiscernible to an ordinary person, and wherein the contact lens is capable of changing the apparent color of the iris of the wearer of the lens while imparting a natural appearance.

2. The contact lens of claim 1, wherein the dots are at least one of round, square, hexagonal, or elongated dots.

3. The contact lens of claim 1, wherein the colored, opaque intermittent pattern further includes a plurality of interstices between the dots, wherein the interstices are non-opaque.

4. The contact lens of claim 3, wherein the non-opaque interstices are translucently colored.

5. The contact lens of claim 3, wherein the non-opaque interstices are uncolored.

6. The contact lens of claim 1, wherein the first and third shades are the same color.

7. A contact lens, comprising: a non-opaque pupil section; an iris section surrounding the pupil section; and a colored opaque intermittent pattern overlying no more than about 30% of the iris section, wherein the colored opaque intermittent pattern comprises an outermost starburst portion comprising dots of a first shade, wherein the first shade includes the darkest color of the pattern; an outer starburst portion comprising dots of a second shade and overlapping at least a portion of the outermost starburst portion, wherein the first and second shades are different from one another; and an inner starburst portion comprising dots of a third shade and overlapping at least a portion of the outer starburst portion, wherein the overlapping of the dots of the outer starburst portion and the inner starburst portion blend together to produce a fourth shade, wherein the overlapping of the dots of the outermost starburst and the outer starburst and the overlapping of the dots of the outer starburst and the inner starburst are indiscernible to an ordinary person, and wherein the contact lens is capable of changing the apparent color of the iris of the wearer of the lens while imparting a natural appearance.

8. The contact lens of claim 7, further comprising an uneven border between each portion.

9. The contact lens of claim 7, wherein the shade of the outermost starburst portion is at least one of black, gray, dark brown, and dark blue.

10. The contact lens of claim 7, wherein the shade of the outer starburst portion is at least one of blue, gray brown, light blue, turquoise, violet, blue violet, aqua, yellow, and green.

11. A contact lens, comprising: a non-opaque pupil section; an iris section surrounding the pupil section; and a colored opaque intermittent pattern overlying no more than about 30% of the iris section, wherein the colored opaque intermittent pattern comprises an outermost starburst portion comprising dots of a first shade; an outer starburst portion comprising dots of a second shade and overlapping at least a portion of the outermost starburst portion, wherein the first and second shades are different from one another; and an inner starburst portion comprising dots of a third shade and overlapping at least a portion of the outer starburst portion, wherein the overlapping of the dots of the outer starburst portion and the inner starburst portion blend together to produce a fourth shade, wherein the overlapping of the dots of the outermost starburst and the outer starburst and the overlapping of the dots of the outer starburst and the inner starburst are indiscernible to an ordinary person, wherein the contact lens is capable of changing the apparent color of the iris of the wearer of the lens while imparting a natural appearance, and wherein the shade of the inner starburst portion is at least one of hazel, yellow, yellow green, brown, yellow brown, gold, and orange.

12. The contact lens of claim 11, wherein the dots of the outermost starburst portion extend to a periphery of the lens.
Contact Lens Description
TECHNICAL FIELD

The present invention relates to colored contact lenses and in particular to such lenses having multiple opaque colored portions that form a pattern that can change the apparent color of the iris while imparting a very natural appearance.

BACKGROUND OF THE INVENTION

Early attempts to modify or enhance the color of one’s eyes utilized colored contact lenses with a simple solidly colored area that covered the iris portion of the eye. However, contact lenses with this type of opaque coloring imparted a very unnatural appearance. Other types of colored contact lenses were developed, such as Wichterle, U.S. Pat. No. 3,679,504, which discloses an opaque lens having an iris of more than a single color artistically drawn or photographically reproduced. However, such lenses did not look natural and as such never achieved commercial success. Other attempts to produce an opaque lens with a natural appearance are disclosed in. U.S. Pat. No. 3,536,386, (Spivak); U.S. Pat. No. 3,712,718 (LeGrand), U.S. Pat. No. 4,460,523 (Neefe), U.S. Pat. No. 4,719,657 (Bawa), U.S. Pat. No. 4,744,647 (Meshel et al.), U.S. Pat. No. 4,634,449 (Jenkins); European Patent Publication No. 0 309 154 (Allergan) and U.K Patent Application No. 2 202 540 A (IGEL).

Commercial success was achieved by the colored contact lens described in Knapp (in U.S. Pat. No. 4,582,402) which discloses a contact lens having, in its preferred embodiment, colored, opaque dots. The Knapp lens provides a natural appearance with a lens that is simple and inexpensive to produce, using a simple one-color printed dot pattern. Although the intermittent pattern of dots does not fully cover the iris, it provides a sufficient density of dots that a masking effect gives the appearance of a continuous color when viewed by an ordinary observer. Knapp also discloses that the printing step may be repeated one or more-times using different patterns in different colors, since upon close examination the iris is found to contain more than one color. The printed pattern need not be absolutely uniform, allowing for enhancement of the fine structure of the iris. The one-color Knapp lenses currently achieving commercial success have their dots arranged in an irregular pattern to enhance the structure of the iris. However, neither the Knapp commercial lenses, nor the Knapp patent disclose or suggest how one would arrange a pattern of dots having more than one color to achieve a more natural appearance.

Various efforts have been made to improve on the Knapp lens. U.S. Pat. No. 5,414,477 to Jahnke discloses the application of the intermittent ink pattern in two or more portions of distinct shades of colorant to provide a more natural appearance.

Other attempts to create a more natural appearing lens include U.S. Pat. No. 5,120,121 to Rawlings, which discloses a cluster of interconnecting lines radiating from the periphery of the pupil portion to the periphery of the iris portion. Further, European Patent No. 0 472 496 A2 shows a contact lens having a pattern of lines that attempts to replicate the lines found in the iris.

Despite these efforts, the contact lens industry continues to seek a low-cost, colored lens that can enhance or modify the eye color, while providing the depth and texture that is inherent in the human iris.

SUMMARY OF THE INVENTION

The present invention is based on the surprising discovery that a pattern having multiple-color opaque portions can achieve a more natural appearing iris if configured properly. The improvement in appearance over the one-color Knapp lenses and the multiple-color Jahnke lenses is startling. Like the one and two color lenses, the lenses of this invention are able to cause a fundamental change in the apparent color of the wearer’s iris, e.g. from dark brown to light blue or green. Although a preferred embodiment of the invention is a three color lens wherein different colors overlap, more than three colors are contemplated, and lenses wherein all three (or more) of the different colors overlap are also contemplated.

One objective of the invention is to provide a colored contact lens with a non-opaque pupil section, an iris section surrounding the pupil section, and a colored, opaque intermittent pattern over the iris section. The elements of the pattern are indiscernible to the ordinary viewer and are made up of a first portion of the elements of the pattern, which is a first shade, and a second portion of the elements of the pattern, which is a second shade different from said first shade, and a third portion of the elements of the pattern, which is a third shade different from said second shade and either different or the same as the first shade. Each of the three portions contain overlapping, mixing and blending elements consisting of or making up, uniform and non-uniform dots, islands of colors, worms, starbursts, corkscrews, spokes, spikes, striations, radial stripes, zig-zags and/or streaks, in combination or separately. Further, each of the overlapping portions may or may not extend from one end of the non-opaque pupil section to the periphery of the iris section. The blending of these various portions creates a lens capable of changing the apparent color of the iris of a person wearing the lens, while imparting a very natural appearance.

Another objective of the invention is to provide a colored contact lens with a non-opaque pupil section, an iris section surrounding the pupil section, and a colored, opaque intermittent pattern over the iris section. The elements of the pattern are indiscernible to the ordinary viewer and are made up of a first portion of the elements of the pattern, or the outermost starburst, which is a first shade, and a second portion of the elements of the pattern, or the outer starburst, which is a second shade different from said first shade, and a third portion of the elements of the pattern, or the inner starburst, which is a third shade different from said second shade and either different or the same as the first shade. The outermost starburst has a greatest concentration of elements located generally outside of the outer starburst, and the outer starburst has a greatest concentration of elements located generally outside the inner starburst. A first uneven border differentiates the outermost and outer starbursts, although there is overlap of the outermost and outer starbursts. A second uneven border differentiates the outer and inner starbursts, although there is overlap between the outer and inner starbursts. Thus, a lens capable of changing the apparent color of the iris of a person wearing the lens and imparting a very natural appearance is provided.

Another objective of the invention is to provide a colored contact lens with a non-opaque pupil section, an iris section surrounding the pupil section, and a colored, opaque intermittent pattern over the iris section, which leaves a substantial portion within the interstices of the pattern non-opaque. The pattern covers at least about 25 percent of the area of the iris section. The elements of the pattern are indiscernible to the ordinary viewer. A first portion of the elements of the pattern, or the outermost starburst, is of a first shade, and a second portion of the elements of the pattern, or the outer starburst, is of a second shade different from said first shade, and a third portion of the elements of the pattern, or the inner starburst, is of a third shade different from said second shade and either different or the same as the first shade. The outermost starburst has a greatest concentration of elements located generally outside of the outer starburst, and the outer starburst has a greatest concentration of elements located generally outside of the inner starburst. A first uneven border differentiates the outermost and outer starbursts although the outermost and outer starbursts overlap, and a second uneven border differentiates the outer and inner starbursts although the outer and inner starbursts overlap. The minimum distance of the first uneven border from the outer perimeter of said iris section is from about 5% to about 60% of the radial width of said iris section. The maximum distance of the first uneven border from the outer perimeter of said iris section is from about 25% to about 95% of the radial width of the iris section. The minimum distance of the second uneven border from the outer perimeter of the iris section is from about 15% to about 75% of the radial width of the iris section, and the maximum distance of said second uneven border from the outer perimeter of the iris section is from about 50% to about 95% of the radial width of the iris section. Thus, a contact lens capable of changing the apparent color of the iris of a person wearing the lens and imparting a very natural appearance is provided.

Another objective of the invention is to provide a colored contact lens with a non-opaque pupil section, an iris section surrounding the pupil section, and a colored, opaque intermittent pattern over the iris section, which leaves a substantial portion within the interstices of the pattern non-opaque. The pattern covers at least about 25 percent of the area of the iris section. The elements of the pattern are indiscernible to the ordinary viewer. A first portion of the elements of the pattern, or the outermost starburst, is of a first shade, and a second portion of the elements of the pattern, or the outer starburst, is of a second shade different from said first shade, and a third portion of the elements of the pattern, or the inner starburst, is of a third shade different from said second shade and either different or the same as the first shade. The outermost starburst has a greatest concentration of elements located generally outside of the outer starburst, and the outer starburst has a greatest concentration of elements located generally on the outside of the inner starburst. A first uneven border differentiates the outermost and outer starbursts although the outermost and outer starbursts overlap, and a second uneven border differentiates the outer and inner starbursts although the outer and inner starbursts overlap. The minimum distance of the first uneven border from the outer perimeter of said iris section is from about 15% to about 50% of the radial width of said iris section. The maximum distance of the first uneven border from the outer perimeter of said iris section is from about 45% to about 95% of the radial width of the iris section. The minimum distance of the second uneven border from the outer perimeter of the iris section is from about 15% to about 65% of the radial width of the iris section, and the maximum distance of said second uneven border from the outer perimeter of the iris section is from about 60% to about 95% of the radial width of the iris section. Thus, a contact lens capable of changing the apparent color of the iris of a person wearing the lens and imparting a very natural appearance is provided.

Yet another objective of the invention is to provide a colored contact lens with a non-opaque pupil section, an iris section surrounding the pupil section, and a colored, opaque intermittent pattern over the iris section, which leaves a substantial portion within the interstices of the pattern non-opaque. The pattern covers an effective amount of the iris section to change the apparent color of the iris. The pattern is made up of multiple portions, each of which is a different shade from the other portion. These portions may or may not overlap each other at multiple points. At least one of the multiple portions is a design that contains either uniform or non-uniform dots, islands of color, worms, starbursts, spokes, spikes, striations, radial stripes, zigzags and/or streaks, or some other design that, along with the other portions, provides a lens capable of changing the apparent color of the iris of the person wearing the lens, while imparting a very natural appearance.

Yet another objective of the invention is to provide a colored contact lens with a non-opaque pupil section, an iris section surrounding the pupil section, and a colored, opaque intermittent pattern over the iris section, which leaves a substantial portion within the interstices of the pattern non-opaque. The pattern, which is made up of elements, covers an effective amount of the iris section to change the apparent color of the iris. The pattern is made up of multiple portions, each of which is a different shade from the other portion. Further, one of these portions is the darkest shade, one of these portions is the lightest shade, and the pattern is configured so that the darkest shaded portion has the greatest concentration of elements located generally outside the other portions. This design provides a lens capable of changing the apparent color of the iris of the person wearing the lens, while imparting a very natural appearance.

Yet another objective of the invention is to provide a colored contact lens with a non-opaque pupil section, an iris section surrounding the pupil section, and a colored, opaque intermittent pattern over the iris section, which leaves a substantial portion within the interstices of the pattern non-opaque. The pattern, which is made up of elements, covers an effective amount of the iris section to change the apparent color of the iris. The pattern is made up of at least three portions, each of which is a different shade from each other portion. Each of the portions overlap the other portion at multiple points. These overlapping portions blend, mix or commingle together, or appear to blend, mix or commingle together, producing unique textures, colors and patterns that make the eye look natural when the contact lens is placed on the eye. To obtain the commingling or blending of the portions, in some instances the different shades will be printed in the same location or close enough that the difference in location is not discernible. This design provides a lens capable of changing the apparent color of the iris of a person wearing the lens, while imparting a very natural appearance.

It can be easily understood that other colored lenses having patterns with multiple portions (having different shades or colors) can be designed and still fall within the scope of the present invention.

The term “non-opaque” as used herein is intended to describe a part of the lens that is uncolored or colored with translucent coloring.

The term “second shade different from said first shade” (or some similar language) as used herein is intended to mean that both shades are of totally different colors, such as blue and hazel; or that both shades are the same basic color, but having different intensities such as light blue and dark blue.

The term “ordinary viewer” is intended to mean a person having normal 20-20 vision standing about 5 feet from a person wearing the lenses of this invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a contact lens pattern in accordance with the present invention;

FIG. 2 illustrates a contact lens pattern indicating an outermost starburst in accordance with the present invention;

FIG. 3 illustrates a contact lens pattern indicating an outer starburst in accordance with the present invention;

FIG. 4 illustrates a contact lens pattern indicating an inner starburst in accordance with the present invention;

FIGS. 5A-5C illustrate three contact lens patterns in accordance with the present invention;

FIG. 6 illustrates a contact lens design based on the combination of FIGS. 5A-5C in accordance with the present invention;

FIG. 7 illustrates a contact lens pattern with elements removed from the periphery of the pattern in accordance with the present invention;

FIG. 8 illustrates a contact lens pattern that is not substantially continuous in accordance with the present invention;

FIG. 9 illustrates three contact lens patterns, one of which is not substantially continuous in accordance with the present invention;

FIG. 10 illustrates three contact lens patterns in accordance with the present invention;

FIG. 11 illustrates three contact lens patterns in accordance with the present invention;

FIG. 12 illustrates three contact lens patterns and the combined contact lens design in accordance with the present invention;

FIG. 13 illustrates three contact lens patterns and the combined contact lens design in accordance with the present invention;

FIG. 14 illustrates three contact lens patterns and the combined contact lens design in accordance with the present invention;

FIG. 15 illustrates a three-pattern contact lens design in accordance with the present invention;

FIG. 16 illustrates a three-pattern contact lens design in accordance with the present invention;

FIG. 17 illustrates a three-pattern contact lens design in accordance with the present invention;

FIG. 18 illustrates a three-pattern contact lens design in accordance with the present invention;

FIG. 19 illustrates a four-pattern contact lens design in accordance with the present invention;

FIG. 20 illustrates a three-pattern contact lens design in accordance with the present invention;

FIG. 21 illustrates a four-pattern contact lens design in accordance with the present invention; and

FIG. 22 illustrates a four-pattern contact lens design in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows a contact lens 10 in accordance with the present invention. It has a non-opaque pupil section 20 in the center of lens, and an annular iris section 22 surrounding the pupil section. For hydrophilic lenses a peripheral section (not shown) surrounds iris section 22. A colored, opaque, intermittent pattern is located over the iris section 22, as show in FIG. 1. The pattern leaves a substantial portion of the iris section within the interstices of the pattern non-opaque. The non-opaque areas of the iris section 22 appear white in FIG. 1.

The elements of the pattern are preferably dots, and especially preferred are dots, some of which run together, as shown in FIG. 1. Certain portions of the iris section 22 are less densely covered with dots than other portions.

The opaque pattern or patterns can be made up of dots having regular or irregular, uniform or non-uniform shapes, for example, round, square, hexagonal, elongated, or other dot shapes. Further, the elements of the pattern may have a shape other than dots, so long as the elements are undescrinable to the ordinary viewer, cover between 10 and 30 percent, preferably about 20 percent of the iris, and leave a substantial portion of the iris section within the interstices of the pattern non-opaque. The patterns that make up the portions of the iris can be islands of color or worms, corkscrews, starbursts, spokes, spikes, striations, radial stripes, zig-zags and streaks. In certain cases, a single color background is used to complement the multi-pattern design. These patterns blend with each other to provide a colored contact lens that enhances the structure of the iris of a person wearing the lens.

The improvement of this invention is a multiple color pattern that greatly improves the natural appearance of the wearer’s iris, even over that of one and two color lenses. To produce this improvement, three (or more) colored patterns are printed in three or more portions. A first portion of the elements are of a first shade and generally have a greatest concentration of dots or other elements located generally on the outside of, but within, the iris section, i.e. at or near the outer perimeter of the annular iris section. This section may be referred to as the outermost starburst. A preferable first outside portion pattern or outermost starburst is shown in FIG. 2. Black, or some other dark color such as gray, dark-brown or dark blue, is most often used as the color of the outermost starburst.

A second portion (the outer starburst) of the elements are a second shade, which is different from the first shade, and has elements with a greatest concentration located generally on the inside of the outermost starburst, and generally, although not always, surrounded by the outermost starburst portion. A preferable second portion or outer starburst appears in FIG. 3. The outer starburst can be many colors, for example, blue, gray, brown, light blue, turquoise, violet, blue-violet, aqua, yellow or green.

A third portion (the inner starburst) of the elements are of a third shade, which is different from the second shade and either the same or different from the first shade. This third portion has a greatest concentration of elements located generally, but not always, on the inside of the other two portions. Generally, the greatest concentration of elements of the third portion is surrounded by the concentration of elements of the other two portions. A preferable third inside portion pattern or inner starburst appears in FIG. 4. A preferred color for the inner starburst is hazel, but other colors to be used include yellow, yellow-green, brown, yellow-brown, gold and orange. FIG. 1, a preferred embodiment of the present invention, shows a combination of FIGS. 2, 3 and 4.

In a preferred embodiment, a first uneven border differentiates the outermost starburst and the outer starburst portions of the pattern elements, however, the elements of the outermost and outer starbursts overlap, mix and blend together, either in actuality or merely in perception, to create the desired effect. A second uneven border differentiates the outer starburst and the inner starburst portions of the pattern. The elements of the outer and inner starbursts overlap, mix and blend together, either in actuality or in perception. If the patterns of FIGS. 2, 3 and 4 are merged to form a three color lens, the uneven edge of the pattern shown in FIG. 2 will merge and overlap with the pattern shown in FIG. 3 to form the first uneven border between the outermost and outer starbursts. Further, the uneven edge of the pattern shown in FIG. 4 will merge and overlap with the pattern shown in FIG. 3 to form the second uneven border between the outer and inner starbursts.

In certain patterns, the outer starburst may contain pattern that extends further toward the periphery of the lens than the pattern of the outermost starburst. In other patterns, the outer starburst may contain pattern that extends further toward the pupil section of the lens than the pattern of the inner starburst.

Alternative embodiments of the present invention include minimum and maximum distances of the uneven borders from the outer perimeter of the iris section. For example in one alternative embodiment, the minimum distance of the first uneven border from the outer perimeter of the iris section is from about 5% to about 60% of the radial width of the iris section, and the maximum distance of the uneven border from the outer perimeter of the iris section is from about 25% to about 95% of the radial width of the iris section, and the minimum distance of the second uneven border from the outer perimeter of the iris section is from about 15% to about 75% of the radial width of the iris section, and the maximum distance of the uneven border from the outer perimeter of the iris section is from about 50% to about 95% of the radial width of the iris section.

In another embodiment, the minimum distance of the first uneven border from the outer perimeter of the iris section is from about 15% to about 50% of the radial width of the iris section, and the maximum distance of the uneven border from the outer perimeter of the iris section is from about 45% to about 95% of the radial width of the iris section, and the minimum distance of the second uneven border from the outer perimeter of the iris section is from about 15% to about 65% of the radial width of the iris section, and the maximum distance of the uneven border from the outer perimeter of the iris section is from about 60% to about 95% of the radial width of the iris section.

In yet another alternative embodiment, the outer starburst pattern may extend to the periphery of the iris section of the contact lens, such that some elements that make up the outer starburst are outside of all of the elements that make up the outermost starburst pattern, and/or the elements that make up the outer starburst pattern extend closer to the pupil section such that some of those elements are inside all of the elements of the inner starburst pattern.

In yet another alternative embodiment, the inner starburst pattern creates an interdigitation configuration with either the outermost starburst pattern or the outer starburst pattern or both patterns. Further, the outermost starburst pattern may create an interdigitation configuration with the outer starburst pattern. In an interdigitation configuration, one pattern intersects another similar to the fingers on one hand placed between the fingers on the other hand in a planar fashion.

Another embodiment is made up of a pattern in which at least one of the portions, and preferably more than one, is made up of a pattern or design which consists of elements which are or create uniform and non-uniform dots, islands of color, worms, corkscrews, starbursts, spokes, spikes, striations, radial stripes, zig-zags and/or streaks (see the examples in FIGS. 5-22). Also, a single color may be used as a background in conjunction with the multi-pattern design (see FIGS. 21 and 22). In these designs the portions may be the same, as in FIGS. 15 and 16, or different, as in FIGS. 19, 20 and 21. For example, if the outermost starburst is the same as that of FIG. 2, and the outer starburst is the one shown in FIG. 3, then the inner starburst may be a design in which radial stripes begin at the inner portion of the iris and travel in a radial direction toward the outer periphery of the iris. In this particular embodiment, the remaining multiple portions, whether there are two or more, are made up of a plurality of elements, which may be similar in design to the foregoing portion, combine to leave a substantial portion within the interstices of the pattern non-opaque.

Alternative embodiments include patterns designed such that the greatest concentration of elements having the darkest color or shaded portion are located generally on the outside of the concentration of the elements of the other portions. In particular, the darkest shaded portion has a greater concentration of elements generally located outside the portions with the lighter shaded portions. Another embodiment places the different portions having different shades such that the darkest portion has the greatest concentration of elements generally located on the outside of the other portions, and the next darkest portion has the greatest concentration of elements generally located outside the remaining portions’ elements. This design continues until the lightest shaded portion has the greatest concentration of elements generally located inside all of the other portions.

Another embodiment includes patterns that are not continuous or concentric. In other words, these patterns, which may be of the type listed above, have noticeable non-opaque areas such that when viewed without the other patterns, the non-opaque areas are clearly visible. However, when these patterns are combined with other patterns, the overlapping, blending and mixing of these patterns creates a design that is able to change the apparent color of the iris, while imparting a very natural appearance.

Producing the opaque portions of the iris section is preferably accomplished by printing the lens three times using the known printing process of Knapp’s U.S. Pat. No. 4,582,402, incorporated herein by reference, and the known printing process of Rawlings’ U.S. Pat. Nos. 5,034,166 and 5,116,112, incorporated herein by reference. Generally, a plate or cliche having depressions in the desired pattern is smeared with ink of the desired shade. Excess ink is removed by scrapping the surface of the plate with a doctor blade leaving the depression filled with ink. A silicon rubber pad is pressed against the plate to pick up the ink from the depressions and then is pressed against a surface of the lens to transfer the pattern to the lens. The printed pattern is then cured to render it unremovable from the lens. Of course, either the anterior or posterior surfaces of the lens may be printed, but printing the anterior surface is presently preferred.

Preferred lenses and ink ingredients used to practice this invention are known and described in Loshaek’s U.S. Pat. No. 4,668,240, incorporated herein by reference. The specific ingredients and target weights are described in detail below. Very briefly, a lens constructured of polymer having –COOH, –OH, or –NH.sub.2 groups is printed with ink containing binding polymer having the same functional groups, opaque coloring substance, and a diisocyanate compound. First a solution of binding polymer and solvent is prepared and this solution is mixed with paste containing the coloring substance to form an ink. A preferred binding polymer solutions have a viscosity of about 35,000 CPS for blue, gray, brown and black, and 50,000 CPS for green. The opaque ink is printed and cured on the lens surface.

Ink pastes and pigments that can be utilized in the present invention can be made in a number of different ways using the ingredients and percentages (by weight) as described below in the ink color charts. For example, a hazel ink paste can be made using 63.49 percent binder solution (by weight), 30.00 percent ethyl lactate, 0.61 percent titanium dioxide, 0.06 percent PCN blue, 4.30 percent iron oxide yellow, and 1.54 percent iron oxide red. Although these colors are used for the preferred embodiments, other colors or variations of the weight percentage of ingredients may be used. The charts below are merely a representative example of the possible inks and pigment levels, and is not a complete list. One of ordinary skill in the art could develop other inks and pigment levels that would provide an enhancing effect to the iris of a person wearing the contact lens.

TABLE-US-00001 INK PASTE COLOR CODE BLUE GRAY Total Wt. (g) 600 3000 600 3000 Weight Target Target Weight Target Target Ingredient Percent Weight Weight Percent Weight Weight Ethyl Lactate 30.55 183.30 916.50 30.75 184.50 922.50 Binder Soln 61.15 366.90 1834.50 59.84 359.10 1795.50 PCN Blue 1.21 7.26 36.30 PCN Green 0.23 1.38 6.90 TiO.sub.2 7.09 42.54 212.70 7.34 44.04 220.20 IO Black 1.83 10.98 54.90 Grinding 600 3000 600 3000 Media

TABLE-US-00002 INK PASTE COLOR BROWN HAZEL Total Wt. (g) 651 3000 651 3000 Weight Target Target Weight Target Target Ingredient Percent Weight Weight Percent Weight Weight Ethyl Lactate 30.00 180.00 900.00 30.00 180.00 900.00 Binder Soln 55.10 330.60 1653.00 63.49 380.94 1904.70 PCN Blue 0.06 0.36 1.80 TiO.sub.2 0.61 3.65 18.3 IO Black 5.70 34.20 171.00 IO Red 3.45 20.70 103.50 1.54 9.25 46.20 IO Yellow 4.30 25.80 129.00 IO Brown 5.75 34.50 172.50 Grinding 600 3000 600 3000 Media

TABLE-US-00003 INK PASTE COLOR GREEN BLACK Total Wt. (g) 651 3000 651 3000 Weight Target Target Weight Target Target Ingredient Percent Weight Weight Percent Weight Weight Ethyl Lactate 28.53 185.73 855.90 23.98 156.11 719.40 Binder Soln 63.85 415.66 1915.50 64.04 416.90 1921.20 PCN Blue 0.03 0.20 0.90 IO Black 11.98 77.99 359.4 Cr.sub.2O.sub.3 7.59 49.41 227.70 Grinding 850 4298 850 4298 Media

TABLE-US-00004 INK PASTE COLOR TURQUOISE ORANGE Total Wt. (g) 600 3000 600 3000 Weight Target Target Weight Target Target Ingredient Percent Weight Weight Percent Weight Weight Ethyl Lactate 30.00 180.00 900.00 30.00 180.00 900.00 Binder Soln 58.16 348.96 1744.80 58.00 348.00 1740.00 PCN Blue 0.63 3.78 18.90 PCN Green 2.25 13.50 67.50 TiO.sub.2 8.88 53.28 266.40 IO Red 6.00 36.00 180.00 Carbazole 0.08 0.48 2.40 Violet Hydrophobic 6.00 36.00 180.00 IO Grinding 600.00 5000.00 850.00 4298.00 Media

Of course, alternative ways to form colored opaque elements of the lens may be used. For example, selected portions of the iris section of a wetted hydrophilic lens may be impregnated with a solution of a first substance, such as barium chloride. Then the lens may be immersed in a solution of a second substance, such as sulfuric acid, that forms an opaque, water-insoluble precipitate with the first substance, for example barium sulfate. Thus an opaque precipitate forms within the lens in a predetermined pattern in the iris section. Next all or at least the opaque pattern of the iris section is colored opaque pattern in accordance with the invention. If the entire iris is colored with translucent tint, then the interstices within the pattern will be translucently colored, but still non-opaque and in accordance with a preferred embodiment of the present invention. Optionally, the pupil section of the lens may be colored by a non-opaque tint, because such tint is not visible when the lens is against the dark pupil present in the eye of the wearer. Other alternative opaquing methods include use of a laser (U.S. Pat. No. 4,744,647) and finely ground particles U.S. Pat. No. 4,460,523.

The process of the present invention for making colored contact lenses is as follows. A transparent contact lens comprising at least a pupil section and an iris section surrounding the pupil section is provided.

If the lens is constructed of a hydrophilic material, it also has a peripheral section surrounding iris section. For hydrophilic material, the steps described below are performed with the material in an unhydrated state. Preferred hydrophilic materials are disclosed by Loshaek in U.S. Pat. No. 4,405,773, incorporated herein by reference.

The colored pattern may be deposited onto iris section of the lens in any manner. A currently preferred method is by offset pad printing, described below in some detail.

A plate as (not shown) is prepared having a flat surface and circular depressions corresponding to the desired dot pattern. To make the pattern shown in FIGS. 2, 3 and 4, each depression should have a diameter of approximately 0.1 mm, and a depth of approximately 0.013 mm. The depressions are arranged to cover an annular shape corresponding to that of the iris section of the lens.

The plate may be made by a technique that is well known for making integrated analog or digital circuits. First, a pattern about 20 times as large as the desired pattern is prepared. Next, the pattern is reduced using well-known photographic techniques to a pattern of the exact desired size having the portion to be colored darker than the remaining area. A flat surface is covered by a photo resist material that becomes water insoluble when exposed to light. The photo resist material is covered with the pattern and exposed to light. The portion of the photo resist pattern is removed by washing with water and the resulting plate is etched to the required depth. Then the remainder of the photo resist material is mechanically removed.

Colorant, comprising a pigment and binder or carrier for the pigment is deposited on the flat surface of the plate and scraped across the pattern with a doctor blade. This causes the depressions to be filled with ink while removing excess ink from flat surface. The colorant may be more or less opaque depending on the degree of color change desired. The opacity may be varied by modifying the proportion of pigment to binder in the colorant. A desired affect may be obtained using a highly opaque colorant or by having a somewhat less opaque colorant and covering a greater portion of the iris section surface.

A pad made of silicon rubber, impregnated with silicon oil for easy release, is pressed against the pattern, removing ink from the depressions. The ink on the pad is allowed to dry slightly to improve tackiness, then pressed against the front surface of the contact lens, which deposits the ink in the desired pattern over the iris section. The pad should have enough flexibility to deform to fit over the convex front surface of the lens. For a more natural effect, the printing step may be repeated one or more times using different patterns in different colors, since upon close examination, the iris’s of many persons are found to contain more than one color. The printed pattern need not be absolutely uniform, allowing for enhancement of the fine structure of the iris.

Next the deposited pattern is treated to render it resistant to removal from the lens under exposure to the ocular fluids that the lens will encounter when placed in the eye. The exact method of preventing removal depends on the material of construction of the lens and the pattern. Mere air drying or heating the lens may suffice. For hydrophilic lenses, the techniques for coating the opaque pattern described in Wichterle, U.S. Pat. No. 3,679,504 (incorporated herein by reference), may be used.

The method for manufacturing a colored contact lens generally includes the steps of applying three portions of colorant to the surface of a transparent contact lens and rendering the colorant resistant to removal from ocular fluids. The printed contact lens has a non-opaque pupil section and an iris section surrounding said pupil section with the three portions of colorant. The first portion of colorant, or outermost starburst, is of a first shade, the second portion of colorant, the outer starburst, is a second shade which is different from the first shade, and the third portion of the colorant, or the inner starburst, is a third shade which is different from the second shade and may or may not be the same as the first shade. The outermost starburst may be located such that the greatest concentration of elements of the outermost starburst are located generally on the outside of, but still within, the iris section, and generally on the outside of the concentration of elements of the outer starburst. The greatest concentration of elements of the outer starburst is located generally on the outside of the greatest concentration of elements of the inner starburst, and a first uneven border differentiates the outermost starburst and the outer starburst, although the outermost starburst and the outer starburst potions will overlap. A second uneven border differentiates the outer starburst and the inner starburst, although the outer and inner starbursts overlap. Thus, a lens capable of changing the apparent color of the iris of a person wearing the lens and imparting a very natural appearance is provided.

The steps used to deposit the intermittent pattern on the lens surface include using a first plate having depressions corresponding to the first portion or outermost starburst and filling the depressions with colorant of the first shade, preferably black. The next step is pressing a first flexible pad against the first plate and subsequently pressing the first flexible pad against the surface of the lens (either side) thereby printing the first portion of the elements.

The next step involves using a second plate having depressions corresponding to the second portion or outer starburst and filling in the depressions with colorant of the second shade which is different from the first shade, preferably blue, green, gray or brown. The next step is pressing the second flexible pad against a second plate and pressing the second flexible pad against the surface of the lens (either the same or the opposite surface) thereby printing the second portion of the elements.

The final step involves using a third plate having depressions corresponding to the third portion or inner starburst and filling the depressions with colorant of the third shade which is different from the second shade and is either the same or different from the first shade, preferably hazel. Pressing a third flexible pad against the third plate and pressing the third flexible pad against said surface of the lens (either side) thereby printing the third portion of the elements.

Although the steps listed above place an order to the printing of the portions on the lens, the order of printing is not important to the present invention and any other order of printing would be covered by the present invention. Further, the process described above may include the maximum and minimum distances, creating the uneven borders, previously listed in the alternative embodiments.

An alternative embodiment for printing the different layers on the iris section of the contact lens provides for ink-jet printing instead of pad printing of each layer. Ink-jet printing is accomplished without the need of pads or plates and can be administered at a higher resolution than pad printing, thereby providing for greater detail of each colored layer and a more natural final pattern on the iris section of the contact lens.

Using ink-jet printing also reduces the number of devices that make contact either with the contact lens or with other devices. For example, a silicon pad must make contact with a plate or cliche initially and then with the contact lens itself. Contact between the parts tends to wear down the parts, which will then require replacements. During the ink-jet process, the micro-nozzles do not physically make contact with the contact lens, nor with any other device. The chance of the micro-nozzle wearing out is thereby reduced.

Further, the ink-jet printer is electronically controlled such that changing from one color layer to a different color layer can be done easily, by computer control. Thus, once a contact lens design is determined and separated into its multiple colored layers, each layer can be applied to the colored contact lens using an ink-jet process, thereby creating a colored contact lens capable of changing the apparent color of the wearer’s iris.

It can be seen that the present invention provides lenses capable of changing the appearance of the wearer’s iris, while allowing visualization of the fine structure thereof. Various changes may be made in the function and arrangement of parts: equivalent means may be substituted for those illustrated and described; and certain features may be used independently from others without departing from the spirit and scope of the invention as defined in the following claims.

1. An ophthalmic fundus contact lens device for delivering laser photocoagulation energy comprising: (a) a body and anterior surface for positioning the device proximate to the eye of a patient, (b) a disc mounted with central and peripheral reflecting mirrors/prisms to redirect laser energy, (c) a micromotor designed to connect and translate rotational force to the central mirror of said disc, (d) a plurality of mirrors or prisms installed internally in an annular fashion within said body, (e) a lens encased for viewing the posterior segment of the ocular anatomy, (f) a control apparatus to coordinate the sequential firing of the laser with the rotation of the central mirror, whereby said assembly will function to deliver laser energy to the eye fundus.

2. The fundus contact lens in claim 1 wherein said body is a truncated cone.

3. The fundus contact lens in claim 1 wherein said plurality of posterior mirrors/prisms circumscribing a circle are eight in number and contiguous.

4. The fundus contact lens in claim 1 wherein said body contains a posterior flange to facilitate insertion and stabilization under the eyelids.

5. The fundus contact lens in claim 1 wherein the posterior end of said body has a radius of curvature approximating the human cornea.

6. The fundus contact lens in claim 1 wherein said body is composed of plastic.

7. The fundus contact lens in claim 1 wherein said said lens for viewing the posterior segment is concave.

8. The fundus contact lens in claim 1 wherein the micromotor is positioned below the central rotating mirror.

9. The fundus contact lens in claim 1 wherein the micromotor is positioned lateral to the mounted central mirror.

10. The fundus contact lens in claim 1 wherein the mounted disc platform is moveable.

11. The fundus contact lens in claim 1 wherein the micromotor is regulated by a control box.
Contact Lens Description
CROSS-REFERENCE TO RELATED APPLICATIONS

This application is related to application Ser. No. 11/024,308, filed Dec. 28, 2004 by one of the present inventors and Ser. No. 11/193,735, filed Jul. 29, 2005 and Ser. No. 11/523,437, filed Sep. 19, 2006 by both of the current inventors.

FEDERALLY SPONSORED RESEARCH

Not applicable

SEQUENCE LISTING OR PROGRAM

Not applicable

BACKGROUND OF THE INVENTION–FIELD OF THE INVENTION

The present invention relates to ophthalmic devices which assist in delivering laser therapy to the eye.

BACKGROUND OF THE INVENTION–PRIOR ART

The worldwide diabetic epidemic is a common cause of visual loss. In the United States prevalence estimates among patients with diabetes reveal approximately 40% show some degree of retinopathy. For severe diabetic retinopathy the incidence is at least 8% and probably higher. Diabetic retinopathy leads the way in causing legal blindness for adults 20-74 years of age. Annually there are 12,000-24,000 new cases diagnosed. Furthermore, the degree and severity of retinal disease usually increases with time. From a global standpoint there are currently at least 171,000,000 patients with diabetes. In 2030 it is projected that 366,000,000 will carry the diagnosis.

Both Type I and Type II diabetes put patients at risk for debilitating retinal problems leading to visual loss. Although Type II is about 20 time more prevalent than Type I severe retinopathy appears in both forms. Significant loss of vision is often due to the proliferative manifestation of the illness. In this scenario abnormal new blood vessels, neovascularization, grow on the retinal or vitreous surface of the eye. Subsequent bleeding, leakage, and traction from these aberrant vascular channels damages the retinal tissue resulting in visual loss.

In the 1970’s a large, randomized multicenter controlled trial demonstrated that the proliferative form (severe–stage 5) of diabetic retinopathy was ameliorated by laser therapy. The Diabetic Retinopathy Study (DRS) became the gold standard showing that panretinal laser photocoagulation could reduce visual loss 50-60% in the neovascular form of the disease. This type of treatment is also used in other eye conditions where abnormal vascular proliferation is evident. They would include neovascular glaucoma, central retinal vein occlusion, and branch retinal vein occlusion. In addition, physicians are given the latitude to treat severe non-proliferative diabetic retinopathy with panretinal laser photocoagulation (PRP) in special circumstances.

The three delivery methods currently used to deliver this treatment all require a high degree of operator dexterity. The slit lamp system requires an operator to manually hold a fundus contact lens on the patient’s anesthetized eye, aim an attenuated laser beam shot by shot, and repetitively depress a foot pedal to activate the energy delivery. The indirect ophthalmoscopic format forces the treating surgeon to hand hold a condensing lens in front of the treated eye, align and tilt a headpiece used to direct the laser beam, and fire the spots via a foot switch. Finally, the endoprobe methodology requires an operating room setting and completion of a vitrectomy. In addition, the surgeon must hold the probe in the internal eye and aim it using an operating microscope with an attendant contact lens. While this modality does have a repeat mode for automated laser firing it still necessitates expert user coordination and an operating theatre.

Regardless of the delivery format a full complement of laser treatment (PRP) usually includes 1500-2000 applications placed in a modified checkerboard pattern inside the eye. Multiple patient visits are the norm for completing this treatment. Not uncommonly a full course of therapy will require 60 minutes of patient and physician time. Upon completion of the procedure a ring or donut configuration of laser treatment spots will cause chorio-retinal scarring that improves the clinical course of proliferative retinopathy.

The slit lamp biomicroscope is the most widely used modality for delivering panretinal laser photocoagulation. Mechanically, a laser emitting source is connected via a fiber optic cable to a biomicroscope. The examiner then places an external fundus contact lens on the patient’s eye after topical anesthetic is applied. Using a micromanipulator on the slit lamp the surgeon can focus an attenuated laser on the patient’s retinal surface. After setting the beam size, power, wavelength, and treatment duration the laser can be fired by activating a foot switch. Typically 500 micron diameter laser spots are placed on the retina–one at a time. Primary absorption of the laser energy is by the retinal pigment epithelial cells and the mechanism of action is by thermal heat transfer. Despite over 35 years of applying treatments in this fashion the exact cellular or chemical reaction that mediates the salutary clinical effect is unknown.

The current methods of performing panretinal laser photocoagulation have a number of disadvantages. First, the procedure is time consuming. It usually requires at least two and more often three office visits to complete a full course of therapy. Not uncommonly a full hour of physician and patient time is spent performing the operation. Second, it requires a significant degree of physician coordination and attention to expertly administer treatment. In most cases the examiner must not only carefully focus, aim, and manually trigger the laser but he/she must fire the shots one at a time. Outside of one expensive laser platform currently on the market there is little automation in the procedure. Third, on a regular basis the laser burns cause patient pain. This can necessitate stopping treatments frequently to let the patient rest, it can necessitate administering retrobulbar anesthesia (injecting a numbing agent through the lid behind the globe of the eye), and it can necessitate stabilizing the patient’s eyelids or head to prevent untoward movements during therapy. Finally, the operation has a number of complications. Some of these, such as operator aiming errors, are related to fatigue in either the physician or patient.

A device that would speed up the procedure or reduce the heavy burden of user coordination would be desirable. Furthermore, an invention that would reduce patient pain would be most welcome for all parties. Prior inventions have attempted solving some of these objectives but most have either failed or become oppressively expensive. U.S. Pat. Nos. 6,066,128 and 5,921,981 to Bahmanyar et al. (2000) (1999) address the time burden issue of administering panretinal photocoagulation. Using an optical device to effectuate splitting a single laser into four beams the authors propose a multispot application of laser with each triggering shot. It follows that 500 applications of treatment might produce 2000 spots at the chorioretinal interface. While this methodology may have some merit in reducing treatment times it fails to address problems of user coordination, aiming errors, patient pain, and treatment complications. Their device would still need to be aimed and triggered one shot at a time. Their device might be more painful delivering four simultaneous applications instead of one. And, their device does not lessen the manual dexterity required to provide a full complement of treatment. Finally, panretinal laser complications such as visual field contraction, nyctalopia, and central visual loss are not addressed by their invention.

In another attempt to cut laser treatment times a California corporation, OptiMedica, has employed a pattern-scanning laser system. Named PASCAL, this method cuts treatment times by placing grids or arrays of burns on the patient’s retina with a single triggered application. A twenty five or fifty six spot array can be chosen employing a semi-automated pattern generation display. The shots are delivered in sequence with short 532 nm laser pulses. While laudably cutting conventional treatment times this laser and software package is not likely to find ubiquitous world wide usage. The platform is expensive, large in size, and not easily mobile. It is expected to cost over $75,000/unit.

In U.S. patent application Ser. No. 11/193/735 Eisenberg and Partono (2005) addressed issues of diminishing treatment times, reducing complications, minimizing operator errors, and improving procedure comfort. Their invention acts as a laser beam diverter so that treatment light is placed in a circumferential pattern. The process of panretinal photocoagulation is not only automated by their invention but the cheaper cost of the device will allow for worldwide distribution. With U.S. patent application Ser. No. 11/523,437 the same inventors (Eisenberg and Partono) refined their approach to automating panretinal laser photocoagulation by advancing a device that was even cheaper to build and worked on a different mechanical principle. Interposed between the hardware of a laser delivery device and the patient’s eye their instrument reflects and diverts laser energy by a system of mirrors or prisms. The net effect is to reduce patient therapy times, reduce operators aiming errors, reduce complications of treatment, and reduce patient pain. Furthermore, the invention is mobile, small, adaptable to most conventional laser machines, and relatively inexpensive. Nothing in the current application reduces the efficacy and the viability of the author’s prior devices. However, in the current invention the process is further simplified, the manufacturing cost is reduced, and a new mechanical mechanism is introduced.

BACKGROUND OF THE INVENTION–OBJECTS AND ADVANTAGES

Thus, several objects and advantages of our invention are; a) to provide a device that is highly mobile and portable; b) to provide an instrument that makes the process of panretinal laser photocoagulation faster; c) to provide a method of performing treatment which decreases operator aiming errors; d) to provide an instrument that reduces the pain of PRP; e) to provide a method that minimizes the complications of laser therapy; f) to provide an article of manufacture that reduces the user coordination required to perform laser surgery; g) to provide an adaptation that increases the safety of the procedure; h) to provide an article of manufacture that automates the delivery of panretinal laser photocoagulation.

Further objects and advantages of our invention will become apparent from a consideration of the drawings and ensuing description.

SUMMARY

The current invention is a fundus contact lens device that will assist in automating panretinal laser photocoagulation. It consists of a body or external housing that is designed to be placed on an anesthetized eye. Internally, a disc with holes is mounted with highly reflective peripheral mirrors or prisms to redirect the pathway of laser treatment light. The center of the disc contains a moveable mirror controlled by a micromotor. Rotation of the central reflecting device diverts light to peripheral mirrors which subsequently redirect the treatment beams. A ring of aligned mirrors or prisms at the bottom of the instrument captures the redirected laser energy and deflects it into the internal eye. The invention is regulated via a cable or remotely by a control box.

DRAWINGS–FIGURES

FIG. 1 shows an exploded view of the device from a lateral view. A ring of mirrors and a special lens are seen at the bottom of the instrument.

FIG. 2 shows the top of the fundus contact in side view with laser light redirected by the central mirror and subsequently diverted again by peripheral mirrors.

FIG. 3 shows the fenestrated disc mounted with mirrors or prisms and a micromotor.

FIG. 4 shows the device connected to a control box.

DRAWINGS–REFERENCE NUMBERS

10 external device casing

12 fenestrated disc

14 micromotor

16 holes associated with peripheral mirrors

18 mounted central reflecting mirror/prism

20 peripheral reflecting mirror/prisms

22 external contact lens housing

24 ring of mirrors for internal reflection

26 concave lens and hole

28 entering laser beam

30 control box

32 attachment cable

DETAILED DESCRIPTION–PREFERRED EMBODIMENT–FIGS. 1-4

The preferred embodiment of the invention is shown in FIGS. 1-4. The external housings 10 and 22 of the device are seen in a lateral exploded view in FIG. 1. Laser light 28 from a source is depicted entering the top of the invention. Initially the highly focused energy strikes the angled central mirror or prism that is mounted on a fenestrated disc 12. After reflection the light strikes one of the peripheral mirrors. Again diversion takes place and the energy is redirected to the ring of peripheral mirrors 24 arranged circumferentially toward the base of the instrument. Redirection of the beams ensues and the light passes through a lens 26 and a hole at the bottom of the fundus contact lens into the internal eye. FIG. 2 depicts the top of the invention in a lateral view with more detail. When the laser beam 28 strikes the central mirror 18 it is noted that micromotor 14 lies near the central reflecting surface. It gives the central mirror/prism rotary capacity such that beam diversion will strike each of the peripheral mirrors 20 arranged and mounted circumferentially on a disc 12. A fenestration 16 immediately adjacent to each peripheral mirror allows the energy to pass through the system unimpeded. FIG. 3 shows an enlarged side view of the central disc 12, holes 16, mirrors 18 and 20, micromotor 14 lying below the central mirror along with laser beam 28 passing through the system. FIG. 4 shows the entire fundus contact lens connected to a control box.

Operation–Preferred Embodiment–FIGS. 1,3,4

The method of using the device to perform panretinal laser photocoagulation (PRP) is consistent with known operator techniques in the current art. It is anticipated that a slit lamp biomicroscope and a laser will be used in conjunction with this delivery system. In this scenario the patient’s cornea is usually anesthetized with topical drops. A coupling agent such as methylcellulose is then applied to the base of the fundus contact lens. The lens is then steadied and placed on the subject’s eye. In the preferred embodiment the base of the fundus contact will have an arrangement of circumferential mirrors as delineated by Eisenberg (2004) in U.S. patent application Ser. No. 11/024,308. At that juncture the treating surgeon sets variable laser parameters such as power, spot size, pulse duration, and wavelength. In addition the physician will choose, via a control box 30 (FIG. 4), the speed of central mirror rotation located within the panretinal laser fundus contact lens. It is anticipated that in the preferred manifestation a large diameter laser beam will be employed. Nothing, however, inhibits the device from being used with a varying range of beam sizes. Furthermore, nothing prevents the instrument from being utilized with laser wavelengths outside the conventional (400-700 nm) range.

With the preferred embodiment an examiner will be able to temporarily rotate the central disc 12 (FIG. 1) of the invention to prevent it from blocking the physician’s view of the internal eye. Once the fundus contact is present on the patient’s eye the posterior lens in the device allows the examiner to center the patient’s macula in the primary position. Thereafter, the peripheral mirrors 24 (FIG. 1) in a ring configuration located in the posterior aspect of the instrument can serve to image and focus the peripheral retina. At that juncture the disc 12 (FIG. 1) mounted with mirrors/prisms can be returned to its functional position so that treatment can be started. Activating a trigger switch will then send laser pulses to the central mirror 18 (FIG. 3) close to micromotor 14 (FIG. 3) The laser beam will then be redirected to a peripheral mirror 20 (FIG. 3). After striking this mirror it will again undergo reflection and a directional change. The light will exit the disc through a fenestration 16 (FIG. 3) located beneath each peripheral reflecting device. Upon leaving the disc platform bundles of laser energy will then hit the corresponding mirrors 24 (FIG. 1) within the ring system at the bottom of the fundus contact. Subsequently, they will exit the device through a lens and hole 26 (FIG. 1) at the base of the invention. At that point the energy will be directed to its final target in the internal eye (retinal/choroid). The entire process from the incident beam to the exit beam will be repeated in an automated fashion. Micromotor 14 (FIG. 3) will serve to rotate the mounted central mirror 18. As the central reflecting device moves it will send laser energy to a different peripheral mirror arranged on disc 12 (FIG. 1). Thus, the light will subsequently be diverted to a different mirror at the bottom of the device. Hence, the anatomical target in the retina will change with each fixed, angular rotation of the central mirror. In this fashion a ring of laser applications will be automatically placed within the eye without manually aiming each application. This methodology will not only speed the process of panretinal photocoagulation it will reduce operator errors. In addition, it will reduce the coordination necessary to perform treatment. If a broad laser beam diameter is used for the treatment a complete course of therapy might be reduced to seconds.

Description–Alternative Embodiments

A number of possibilities exist for alternative embodiments of this invention. First, the shape of the external housing of the device in the preferred embodiment is a truncated cone. This is in conformity with most of the current fundus contacts that are commercially available at the present time. However, nothing prevents the device from taking another conformation. It could, for example, easily fit inside a cylindrical body. Second, the mechanism to move the central disc with mounted mirrors so as to allow an examiner to focus on the posterior segment of the eye, has a number of possibilities. In the preferred model the disc is connected to a rod or a wheel that allows the treating surgeon to manually rotate the platform of mirrors. However, this could be achieved electronically without deviating from the spirit of the invention. Furthermore, the internal disc suspending the reflective elements could be hinged to the fundus contact body and swing in and out of place, manually or electronically, at the command of the treating surgeon. Third, the circumferential mirror system at the base of the invention (the last reflective element in the invention prior to the laser light entering the eye) could have a variable number of mirrors/prisms. While the preferred embodiment is drawn with eight the invention could be made six, twelve, or any other number. In addition, the shape of these reflective elements is variable. They might be made as rectangular, semicircular, truncated cones, or triangular. The specific shape of the mirrors is not central to the thesis of the device. Fourth, the regulation of the instrument is depicted with a cable connection to a control box. However, a wireless control might easily be used. Or the electrical circuitry of the laser and biomicroscope might be integrated so as to control the invention. Fifth, one skilled in the art might construct an instrument mimicking the current invention by arranging multiple barrels of laser beams designed to discharge in successive fashion. If the tubes were arranged in a circular fashion and the mirrors of the fundus contact were designed to receive the laser delivery the net result would be analogous to the current device. The successive firing of each laser source or the simultaneous discharges from all would produce a ring of photocoagulation consistent with the current invention. Finally, the position of the micromotor in the device is optional. While the current embodiment is depicted with the micromotor lying below the central reflecting mirror it can easily lie elsewhere. For example, the small motor might occupy a space lateral to the central mirror. It could protrude from the body of the contact lens in an alternative embodiment. In this arrangement it would be connected to the central mirror via a tube or gearing system that would enable it to rotate the central reflecting device. Simultaneously, an examiner might be able to rotate the micromotor and effectuate a repositioning of the central disc with mounted mirrors. From the foregoing discussion it is evident that the exact placement of the micromotor in the device is not critical to the operating principle of the instrument.

Advantages

From the previous description a number of the advantages of our invention become evident: a) The time to complete panretinal laser photocoagulation will be shortened. A rotating laser beam will help automate the treatment process. b) The device will reduce the user coordination involved with the current treatment strategy since the operator will not have to manually aim and trigger each individual application. c) This fundus contact lens will be relatively small and easily portable. Thus, automating a treatment will not require a large hardware platform of heavy and expensive equipment. d) Aiming errors by the treating surgeon will be diminished. The invention will promote the automatic delivery of laser energy to the interior eye without the manual use of a micromanipulator. e) This treatment adaptation will reduce the patient pain associated with panretinal laser therapy. If used either in conjunction with a broad beam laser or with decreased pulse durations the net energy delivered to the retina will be less. This, along with faster delivery times, will minimize patient discomfort. f) Enhanced safety will result from the instrument. Speeding and automating the process of panretinal laser treatment will result in less fatigue for the patient and the surgeon. Furthermore, it will cut the incidence of misdirected laser energy due to operator errors. g) The complications of panretinal laser surgery will be reduced. If less energy is delivered to the eye the side effects of current treatments should be less. This would include untoward results such as visual field contraction, contrast sensitivity reduction, and nyctalopia. It is even possible macular edema might be lessened by our invention. h) The apparatus will assist in automating a process which is heavily burdened with manual input.

CONCLUSIONS, RAMIFICATIONS, SCOPE

Thus, the reader will see that a specialized fundus contact lens can be used to provide a faster and safer method for performing panretinal laser photocoagulation. This is accomplished by diverting laser light energy within an instrument that is held on the eye during treatment. By mechanically rotating a central mirror that receives laser energy the light can be redirected to mounted peripheral mirrors/prisms which divert the energy in a circular configuration. In this fashion an annular ring of photocoagulation can be delivered to the internal eye. The effects of the invention will be to speed the process of treatment, to reduce patient pain, to reduce operator fatigue, to minimize aiming errors, and to minimize the complications of the procedure.

The above description contains many specificities and these should not be construed as limitations on the scope of the invention. Instead they should be seen as exemplifications of the preferred embodiment. Many variations are possible aside from the ones previously discussed. For example, a rod or cylindrical attachment might extend from the body of the contact lens and connect to the mirror mounted disc. This might facilitate rotating or moving the reflective platform so that the examiner could use the posterior lens in the contact to view the internal eye. Alternatively, the plate of mirrors might exist in a configuration that allows it to be removed entirely from the interior of the fundus contact. Then subsequent reinsertion, after checking the patient’s eye position, would allow therapy to proceed.

It is apparent that the scope of the invention should be determined by the appended claims and their equivalents.

1. A method for designing a multifocal lens, comprising the steps of: a.) selecting a resting pupil size; b.) calculating a pupil size when viewing near objects; c.) selecting a ratio of far vision correction area to near vision correction area for a lens; d.) calculating values for the ratio as a function of an add power for viewing near and far objects using the resting and near viewing pupil diameters; and e.) adding an amount of optical convergence to the lens.

2. The method of claim 1, wherein step b.) further comprises (i) determining a total add power required by a lens wearer and (ii) calculating a residual add power.

3. The method of claim 1, wherein the ratio of far vision correction area to near vision correction area ratio is 70 to 30.

4. The method of claim 2, wherein the ratio of far vision correction area to near vision correction area ratio is 70 to 30.

5. A lens according to the method of claim 1.

6. A lens according to the method of claim 2.

7. A lens according to the method of claim 3.

8. A lens according to the method of claim 4.

9. The lens of claim 5, comprising an optic zone having a first zone and second annular zone surrounding the first zone and a horizontal prism having a base oriented in a nasal direction.

10. The lens of claim 6, comprising an optic zone having a first zone and second annular zone surrounding the first zone and a horizontal prism having a base oriented in a nasal direction.

11. The lens of claim 7, comprising an optic zone having a first zone and second annular zone surrounding the first zone and a horizontal prism having a base oriented in a nasal direction.

12. The lens of claim 8, comprising an optic zone having a first zone and second annular zone surrounding the first zone and a horizontal prism having a base oriented in a nasal direction.
Contact Lens Description
FIELD OF THE INVENTION

The invention relates to multifocal ophthalmic lenses. In particular, the invention provides methods for designing contact lenses that provide correction for presbyopia and that take into account pupil size and vergence.

BACKGROUND OF THE INVENTION

As an individual ages, the eye is less able to accommodate, or bend the natural lens, to focus on objects that are relatively near to the observer. This condition is known as presbyopia. Similarly, for persons who have had their natural lens removed and an intraocular lens inserted as a replacement, the ability to accommodate is absent.

Among the methods used to correct for the eye’s failure to accommodate are contact lenses that have more than one optical power. In particular, multifocal contact and intraocular lenses have been developed in which zones of distance and near, and in some cases intermediate, power have been provided. However, no one of the known designs has proven to be widely successful with lens wearers.

DETAILED DESCRIPTION OF THE INVENTION AND PREFERRED EMBODIMENTS

The invention provides methods for designing a contact lenses, lenses according to the design method, and methods for producing the lenses, which lenses provide presbyopic correction by taking into account pupil size and vergence in their design. The lenses of the invention are advantageous in that their design augments the eye’s accommodative gain, meaning the increase in plus power measured in diopters when the eye responds to an accommodative or convergence stimulus. Additionally, the design takes advantage of the eye’s residual accommodation amplitude, or the total accommodative ability of the eye based on the age and ocular physiology of the individual.

The invention provides a method for the design of a multifocal lens comprising, consisting essentially of, and consisting of: a.) selecting a resting pupil diameter; b.) calculating a pupil diameter when viewing near objects; c.) selecting a ratio of near vision correction area to far vision correction area for a lens; d.) calculating values for the ratio as a function of an add power for viewing near and far objects using the resting and near viewing pupil diameters; and e.) adding an amount of optical convergence for the lens.

In a first step of the method of the design of the lens of the invention, the pupil size is taken into account in the following manner. A resting pupil diameter, or pupil diameter for viewing objects more than about 500 cm from the eye, is selected based on an average of population data or a measurement of an individual’s pupil. The pupil diameter when viewing near objects, or objects less than about 100 cm from the eye, as a function of prescribed add power is then calculated based on the prescribed add power, the residual accommodation and the resting pupil diameter. To perform this calculation, the total add power required by the lens wearer must be determined. A portion of this add power will be supplied by the prescribed add power of the lens and a portion by the residual accommodation of the lens wearer’s eye.

The residual add power may be calculated by subtracting the prescribed add power from the total add power required. A determination of the total amount of add power required will be based on optics, clinical experience that determines add powers for product which powers generally are available in the range from 1.00 to 3.00D, and the known studies of the accommodation needs of presbyopic populations as a function of age. The residual accommodation may be a physiologically determined quantity, mainly dependent on age and typically varies from 10+D for people less than about 15 years of age to less than 0.5D in those more than about 65 years old. For illustration purposes, it may be assumed that, to read clearly at 35 cm from the eye, an individual may require a total add power of 2.85D. The prescribed add power will be 1.00D and the residual add power will be 1.65D.

It is also known that there is a functional dependence between pupil size and accommodation measured at a constant luminance. Based on this, the accommodative response has been computed by obtaining the inverse of the object distance and has been measured over a wide range of light intensities. For example, such data was reported in Glen Myers, Shirin Berez, William Krenz and Lawrence Stark, Am. J. Physiol. Regul. Integr. Comp. Physiol., 258: 813-819 (1990). Such data is the basis for the pupil constriction model that assumes independent linear interaction between accommodative stimulus and increase in luminance as shown by the equation: A=A.sub.0-B-C (I) wherein: A is the pupil size; A.sub.0 is the resting pupil size; B is 1/object distance in meters; and C is log FL. Measured clinically, B is 0.27 and C is 0.19. Assuming a luminance of 1.0 FL, Equation I can be rewritten as: A=A.sub.0-0.27D (II) wherein D is the residual accommodation in the lens wearer’s eye. Applying Equation II to the example above in which 2.85D is the required total add power and assuming a resting pupil diameter of 7.5 mm, Table 1 below shows the calculated values for the difference between the resting pupil diameter and pupil diameter resulting from application of Equation II.

TABLE-US-00001 TABLE 1 Prescribed Residual Reduction in Pupil Size When Add Power Accommodation Pupil Size Viewing Near Objects 1.0D 1.85D 0.50 mm 7.0 mm 1.5D 1.35D 0.36 mm 7.14 mm 2.0D 0.85D 0.23 mm 7.27 mm 2.5D 0.35D 0.09 mm 7.41 mm

The ratio (A.sub.F/A.sub.N) of area of the lens to be used for correcting the wearer’s distance vision, or of the far zone of the lens, versus that used for correcting near vision, or the near vision zone, to be provided by the lens design may be then selected and used to calculate the area of the lens to be allocated to near and far vision optics. The selection may be based on the measured visual acuity and contrast sensitivity at far and near luminance ranges for either an individual or the average for a population of individuals. A preferred ratio for refractive optics is 70/30, in favor of the far vision zones, when viewing near objects. A preferred ratio for a diffractive optic will be 50/50.

The values for A.sub.F/A.sub.N can be calculated as a function of add power for viewing near and far objects, the results for a ratio of 70/30 which are shown on Table 2. The area ratio in this calculation is given by the square of the ratio of diameters.

TABLE-US-00002 TABLE 2 Prescribed Add Power A.sub.F/A.sub.N(Near Objects) A.sub.F/A.sub.N(Far Objects) 1.0D 1.89 (65:35) 2.33 (70/30) 1.5D 2.02 (67:33) 2.33 (70/30) 2.0D 2.13 (68:32) 2.33 (70/30) 2.5D 2.25 (69/31) 2.33 (70/30)

For example, based on a pupil size of 7.5 mm when viewing distant objects and 7.0 mm when viewing near objects, the area of optic provided for far vision is .pi.(7.5/2).sup.2.times.0.70 sq. mm and the area provided for near vision is .pi.(7.5/2).sup.2.times.0.30 sq. mm. When viewing near objects, the area is reduced to .pi.(7.0/2).sup.2. The ratio of the near vision area to the total optical area is .pi.(7.5/2).sup.2.times.0.30/.pi.(7.0/2).sup.2 or (7.5/7.0).sup.2.times.0.30=1.072.times.0.30=1.145.times.0.3=0.343 or 34.3%. Thus, 65.7% remains for the far vision zone.

Thus, the method of the invention permits the lens designer to provide a greater portion of the pupillary aperture to the retinal image of far object images without compromising the luminance of near object images. This is due to the fact that the near vision zone is placed within the pupillary area of the constricted pupil and the far vision zone is disposed within the pupillary aperture of the pupil at rest, or the unaccommodated pupil and pupillary constriction on accommodation excludes some of the far vision zone.

In another step of the method of the invention, an amount of vergence, or optical convergence, effective to bring both eyes of an individual to a common focus on a viewed object is incorporated into the lens. The amount of optical convergence added will depend upon the add power designed into the lens, with the amount of optical convergence increasing as the amount of add power increases. Typically, an amount up to about 2.0D may be added.

The optical convergence preferably is incorporated into the lens by adding a base-in prism, meaning horizontal prism with the base oriented in the nasal direction of the lens. Optical convergence may, in monovision designs, also be incorporated by adding sufficient plus power to the lens to reduce the overall accommodative need. Also, convergence may be added by decentering the center of the near vision zone from the lens’ geometric center.

The preferred lens resulting from the method of the invention is a bifocal in which the optic zone contains two, radially symmetric zones: a first zone that is a central zone and a second zone that is an annular zone that surrounds the central zone. The far and near vision zones are located within the pupillary aperture of the eye at rest. The near vision zone is located within the pupillary aperture when the eye is fully accommodated and has an area of about 30 to about 50% of the area of the optic zone inside of the pupillary aperture for near vision, while the radius of the optic zone matches or exceeds the pupillary aperture for far vision. The ratio of the area of near to far vision is calculated as described above, the ratio favoring far vision when the eye is unaccommodated and near vision when the eye is accommodated. Additionally, the near vision zone is provided with a horizontal prismatic correction with the base oriented in the nasal direction. In the preferred embodiment, the location of the near vision zone is specified to be within the pupillary aperture of the accommodated eye, but no limitation is placed on its location relative to the pupil’s center.

In the lenses of the invention, the optic zone, and the near and far vision zones within, may be on the front surface, or object side surface, the back surface, or eye side surface of the lens, or split between the front and back surfaces. Cylinder power may be provided on the back, or concave surface of the lens in order to correct the wearer’s astigmatism. Alternatively, the cylinder power may be combined with either or both of the distance and near vision powers on the front surface or back surface. In all of the lenses of the invention, the distance, intermediate and near optical powers may be spherical or aspheric powers.

Contact lenses useful in the invention preferably are soft contact lenses. Soft contact lenses, made of any material suitable for producing such lenses, preferably are used. Illustrative materials for formation of soft contact lenses include, without limitation silicone elastomers, silicone-containing macromers including, without limitation, those disclosed in U.S. Pat. Nos. 5,371,147, 5,314,960, and 5,057,578 incorporated in their entireties herein by reference, hydrogels, silicone-containing hydrogels, and the like and combinations thereof. More preferably, the surface is a siloxane, or contains a siloxane functionality, including, without limitation, polydimethyl siloxane macromers, methacryloxypropyl polyalkyl siloxanes, and mixtures thereof, silicone hydrogel or a hydrogel, such as etafilcon A.

A preferred lens-forming material is a poly 2-hydroxyethyl methacrylate polymers, meaning, having a peak molecular weight between about 25,000 and about 80,000 and a polydispersity of less than about 1.5 to less than about 3.5 respectively and covalently bonded thereon, at least one cross-linkable functional group. This material is described in U.S. Pat. No. 6,846,892 incorporated herein in its entirety by reference. Suitable materials for forming intraocular lenses include, without limitation, polymethyl methacrylate, hydroxyethyl methacrylate, inert clear plastics, silicone-based polymers, and the like and combinations thereof.

Curing of the lens forming material may be carried out by any means known including, without limitation, thermal, irradiation, chemical, electromagnetic radiation curing and the like and combinations thereof. Preferably, the lens is molded which is carried out using ultraviolet light or using the full spectrum of visible light. More specifically, the precise conditions suitable for curing the lens material will depend on the material selected and the lens to be formed. Polymerization processes for ophthalmic lenses including, without limitation, contact lenses are well known. Suitable processes are disclosed in U.S. Pat. No. 5,540,410 incorporated herein in its entirety by reference.

The contact lenses of the invention may be formed by any conventional method. For example, the optic zone may be produced by diamond-turning or diamond-turned into the molds that are used to form the lens of the invention. Subsequently, a suitable liquid resin is placed between the molds followed by compression and curing of the resin to form the lenses of the invention. Alternatively, the zone may be diamond-turned into lens buttons.