Polymers and methods for ophthalmic applications

Abstract

Novel methods and materials particularly useful for ophthalmic applications and to methods for making and using the same are disclosed herein. More particularly, relatively soft, optically transparent, foldable, high refractive index materials particularly suited for use in the production of intraocular lenses, contact lenses, and other ocular implants and to methods for manufacturing and implanting IOLs made therefrom are disclosed.

Claims

1. A copolymer comprising: (a) vinyl carbazole from 18% to 28% by weight of the copolymer; (b) 2-(2-ethoxyethoxy)ethyl acrylate from 39% to 49% by weight of the copolymer; (c) hydroxyethyl acrylate from 23% to 33% by weight of the copolymer; and (d) a crosslinker from 2.5% to 3.5% by weight of the copolymer.

2. The copolymer of claim 1, wherein the copolymer further comprises an ultraviolet light absorbing material.

3. The copolymer of claim 1, wherein the copolymer has an Equilibrium Water Content (EWC) from 5% to 15%.

4. The copolymer of claim 1, wherein the vinyl carbazole is about 20% by weight of the copolymer.

5. The copolymer of claim 1, wherein the vinyl carbazole is about 24% by weight of the copolymer.

6. The copolymer of claim 1, wherein the 2-(2-ethoxyethoxy)ethyl acrylate is about 45% by weight of the copolymer.

7. The copolymer of claim 1, wherein the hydroxyethyl acrylate is about 30% by weight of the copolymer.

8. The copolymer of claim 1, wherein the hydroxyethyl acrylate is about 26% by weight of the copolymer.

Description

DETAILED DESCRIPTION

(1) All references to the Periodic Table of the Elements refer to the Periodic Table of the Elements published and copyrighted by CRC Press, Inc., 1990. Also, any references to a Group or Groups shall be to the Group or Groups reflected in this Periodic Table of the Elements using the IUPAC system for numbering groups. Unless stated to the contrary, implicit from the context, or customary in the art, all parts and percent are based on weight and all test methods are current as of the filing date of this disclosure. For purposes of United States patent practice, the contents of any referenced patent, patent application or publication are incorporated by reference in their entirety (or its equivalent US version is so incorporated by reference) especially with respect to the disclosure of synthetic techniques, product and processing designs, polymers, catalysts, definitions (to the extent not inconsistent with any definitions specifically provided in this disclosure), and general knowledge in the art.

(2) The numerical ranges in this disclosure are approximate, and thus may include values outside of the range unless otherwise indicated. Numerical ranges include all values from and including the lower and the upper values, in increments of one unit, provided that there is a separation of at least two units between any lower value and any higher value. As an example, if a compositional, physical or other property, such as, for example, molecular weight, viscosity, melt index, etc., is from 100 to 1,000, the intent is that all individual values, such as 100, 101, 102, etc., and sub ranges, such as 100 to 144, 155 to 170, 197 to 200, etc., are expressly enumerated. For ranges containing values which are less than one or containing fractional numbers greater than one (e.g., 1.1, 1.5, etc.), one unit is considered to be 0.0001, 0.001, 0.01 or 0.1, as appropriate. For ranges containing single digit numbers less than ten (e.g., 1 to 5), one unit is typically considered to be 0.1. These are only examples of what is specifically intended, and all possible combinations of numerical values between the lowest value and the highest value enumerated, are to be considered to be expressly stated in this disclosure. Numerical ranges are provided within this disclosure for, among other things, the weight percent of components within compositions disclosed herein.

(3) The term “about,” as used herein in conjunction with a numerical range, modifies that range by extending the boundaries above and below the numerical values set forth. In one embodiment, the term “about” is used herein to modify a numerical value above and below the stated value by a variance of 10%. Therefore, about 50% includes the range of 45%-55%.

(4) As used with respect to a chemical compound, unless specifically indicated otherwise, the singular includes all isomeric forms and vice versa (for example, “hexane”, includes all isomers of hexane individually or collectively). The terms “compound” and “complex” are used interchangeably to refer to organic-, inorganic- and organometal compounds. The term, “atom” refers to the smallest constituent of an element regardless of ionic state, that is, whether or not the same bears a charge or partial charge or is bonded to another atom.

(5) “Comprising,” “including,” “having” and like terms are not intended to exclude the presence of any additional component, step or procedure, whether or not the same is specifically disclosed. In order to avoid any doubt, all processes claimed through use of the term “comprising” may include one or more additional steps, pieces of equipment or component parts, and/or materials unless stated to the contrary. In contrast, the term, “consisting essentially of” excludes from the scope of any succeeding recitation any other component, step or procedure, excepting those that are not essential to operability. The term “consisting of” excludes any component, step or procedure not specifically delineated or listed. The term “or,” unless stated otherwise, refers to the listed members individually as well as in any combination.

(6) “Composition” and like terms refer to a mixture or blend of two or more components.

(7) “Copolymer” refers to polymers prepared from two different monomers, and polymers prepared from more than two different monomers, e.g., terpolymers, tetrapolymers, etc.

(8) The term “polymer” (and like terms) is a macromolecular compound prepared by reacting (i.e., polymerizing) monomers of the same or different type. “Polymer” includes homopolymers and copolymers.

(9) Materials with high refractive indexes are desirable to allow manufacturers to manufacture thinner IOLs. A thin IOL or thin IOL optic is critical in enabling a surgeon to minimize incision size. Keeping the surgical incision size to a minimum reduces intraoperative trauma and postoperative complications. A thin IOL is also critical for accommodating certain anatomical locations in the eye such as the anterior chamber and the ciliary sulcus. IOLs may be placed in the anterior chamber for increasing visual acuity in both aphakic and phakic eyes and placed in the ciliary sulcus for increasing visual acuity in phakic eyes.

(10) Compositions and polymers disclosed herein have the flexibility required to allow the same to be folded or deformed so that IOLs made therefrom may be introduced into an eye through the smallest possible incision.

(11) In one embodiment, the novel materials are copolymers, trimers, tetramers, etc., comprising at least two monomeric components:

(12) A hydrophobic monomer, and a hydrophilic monomer. In one embodiment, a crosslinker generally is included. In another embodiment, a UV absorber is included.

(13) In one embodiment, the compositions comprise multimers including: a first monomer containing an aromatic, carbazole and/or naphthyl moiety, the aromatic/carbazole/naphthyl moiety monomer being present in the composition at a concentration of at least about 20% and preferably up to about 35-80%.

(14) In another embodiment, the composition further includes a second monomer with a hydrophobic homopolymer, the hydrophobicity being defined as the homopolymer having a surface tension of about 50 dyn/cm or less, the second monomer being present in the copolymer in an amount of at least about 20 weight %, preferably about 50-60 weight %.

(15) In yet another embodiment, the composition then includes at least about 10 weight % of a hydrophilic monomer, preferably about 20-30 weight %. The composition then includes a crosslinking monomer, the crosslinking monomer being present at a concentration in the range up to about 10 weight percent, preferably of about 1 weight % to about 8 weight %.

(16) In still another embodiment, the disclosure relates to compositions comprising a first monomer containing an aromatic, carbazole and/or naphthyl moiety, and one or more hydrophilic monomers. In yet another embodiment, the aromatic/carbazole/naphthyl moiety monomer is present in the composition at a concentration of at least about 20%. In still another embodiment, aromatic/carbazole/naphthyl moiety monomer is present in the composition at a concentration from about 35 to about 80%.

(17) In still another embodiment, the disclosure relates to a copolymer comprising a monomer containing an aromatic, carbazole and/or naphthyl moiety, a first hydrophilic monomer, and a second hydrophilic monomer.

(18) In still another embodiment, the disclosure relates to a copolymer comprising a monomer containing an aromatic, carbazole and/or naphthyl moiety, the aromatic/carbazole/naphthyl moiety monomer being present in the copolymer at a concentration from about 20% by weight to about 30% by weight; and one or more hydrophilic monomers from about 70% by weight to about 80% by weight.

(19) In another embodiment, the copolymer further comprises a crosslinker. In still other embodiments, the copolymer further comprises a UV absorber. In yet another embodiment, the copolymer further comprises an initiator, including but not limited to Azobisisobutyronitrile (AIBN).

(20) In still another embodiment, the disclosure relates to a copolymer comprising a monomer containing an aromatic, carbazole and/or naphthyl moiety, a first hydrophilic monomer, a second hydrophilic monomer, a UV absorber, a crosslinker, and an initiator.

(21) In another embodiment, one or more hydrophilic monomers comprise from about 50% to about 80% by weight of the copolymer, or from about 55% to about 80% by weight of the copolymer or from about 60% to about 80% by weight of the copolymer, or from about 65% to about 80% by weight of the copolymer, or from about 70% to about 80% by weight of the copolymer, or from about 75% to about 80% by weight of the copolymer.

(22) In yet another embodiment, one or more hydrophilic monomers comprise from about 50% to about 75% by weight of the copolymer, or from about 50% to about 70% by weight of the copolymer, or from about 50% to about 65% by weight of the copolymer, or from about 50% to about 65% by weight of the copolymer, or from about 50% to about 55% by weight of the copolymer.

(23) In yet another embodiment, one or more hydrophilic monomers comprise from about 62% to about 80% by weight of the copolymer, or from about 64% to about 80% by weight of the copolymer, or from about 66% to about 80% by weight of the copolymer, or from about 68% to about 80% by weight of the copolymer, or from about 72% to about 80% by weight of the copolymer, or from about 74% to about 80% by weight of the copolymer, or from about 76% to about 80% by weight of the copolymer, or from about 78% to about 80% by weight of the copolymer.

(24) In yet another embodiment, one or more hydrophilic monomers comprise from about 66% to about 78% by weight of the copolymer, or from about 66% to about 76% by weight of the copolymer, or from about 66% to about 74% by weight of the copolymer, or from about 66% to about 72% by weight of the copolymer, or from about 66% to about 70% by weight of the copolymer, or from about 66% to about 68% by weight of the copolymer.

(25) In yet another embodiment, one or more hydrophilic monomers comprise from about 67% to about 78% by weight of the copolymer, or from about 68% to about 78% by weight of the copolymer, or from about 69% to about 78% by weight of the copolymer, or from about 70% to about 78% by weight of the copolymer, or from about 71% to about 78% by weight of the copolymer, or from about 72% to about 78% by weight of the copolymer, or from about 73% to about 78% by weight of the copolymer, or from about 74% to about 78% by weight of the copolymer, or from about 57% to about 78% by weight of the copolymer, or from about 76% to about 78% by weight of the copolymer, or from about 77% to about 78% by weight of the copolymer.

(26) In yet another embodiment, one or more hydrophilic monomers comprise from about 67% to about 75% by weight of the copolymer, or from about 68% to about 75% by weight of the copolymer, or from about 69% to about 75% by weight of the copolymer, or from about 70% to about 75% by weight of the copolymer, or from about 71% to about 75% by weight of the copolymer, or from about 72% to about 75% by weight of the copolymer, or from about 73% to about 75% by weight of the copolymer, or from about 74% to about 75% by weight of the copolymer.

(27) Suitable hydrophilic monomers (i.e., monomers whose homopolymers are hydrophilic in accordance with the compositions, methods, and polymers disclosed herein) include but are not limited to 2-hydroxy-ethylacrylate, 2-hydroxyethylmethacrylate, acrylamide, N-ornithine acrylamide, N-(2-hydroxypropyl)acrylamide, polyethyleneglycol acrylates, polyethyleneglycol methacrylates, N-vinyl pyrolidone, N-phenylacrylamide, dimethylaminopropyl methacrylamide, acrylic acid, benzylmethacrylamide, 4-hydroxybutylmethacrylate, glycerol mono methacrylate, glycerol mono acrylate, 2-sulfoethylmethacrylate, phenoxyethyl acrylate, phenoxy ethyl methacrylate, 2-(2-ethoxyethoxy)ethyl acrylate, 2-(2-ethoxyethoxy)ethyl methacrylate, furfuryl acrylate, furfuryl methacrylate, and methylthioethylacrylamide. Any of the above-referenced hydrophilic monomers can be a first or a second hydrophilic monomer in a composition.

(28) Suitable hydrophobic monomers (i.e., monomers whose homopolymers are hydrophobic in accordance with the compositions, methods, and polymers disclosed herein) include but are not limited to Lauryl methacrylate, Lauryl acrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, n-decyl acrylate, n-decyl methacrylate, hexyl acrylate, hexyl methacrylate, stearyl acrylate, stearyl methacrylate, isodecyl acrylate, isodecyl methacrylate, isobornyl acrylate, isobornyl methacrylate, vinyl laurate, vinyl stearate, 1-hexadecyl acrylate, 1-hexadecyl methacrylate, n-myristyl acrylate, n-myristyl methacrylate, n-dodecyl methacrylamide, butyl acrylate, n-butyl methacrylate, isooctyl acrylate, isotridecyl acrylate, isooctyl methacrylate, and isotridecyl methacrylate.

(29) Suitable crosslinkers include for example but are not limited to ethylene glycol dimethacrylate (EGDMDA), diethylene glycol dimethacrylate, triethylene glycol dimethacrylate and poly(ethylene glycol) dimethacrylate wherein ethylene glycol dimethacrylate is preferred. Suitable initiators include for example but are not limited to azobis(isobutyronitrile), 2,2′-azobis(2,4-dimethylvaleronitdle), 2,2′-azobis (methylbutyronitrile), 1,1′-azobis (cyanocyclo-hexane), di-t-butyl peroxide, dicumyl peroxide, t-butylcumyl peroxide, 2,5-dimethyl-2,5-bis(2-ethylhexanoyl peroxy)hexane, t-butyl peroxyneodecanote, t-butyl peroxy 2-ethylhexanoate, di(4-t-butyl cyclohexyl) peroxydicarbonate, t-butyl peroxypivalate, decanoyl peroxide, lauroyl peroxide, benzoyl peroxide, 2,4-pentanedione peroxide, di(n-propyl) peroxydicarbonate, t-amyl peroxyneodecanoate and t-butyl peroxyacetate wherein 2,2′-azobis(isobutyronitrile) is preferred. Suitable ultraviolet light absorbers include for example but are not limited to beta-(4-benzotriazoyl-3-hydroxyphenoxy) ethyl acrylate, 4-(2-acryloxyethoxy)-2-hydroxybenzophenone, 4-methacryloxy-2-hydroxybenzo-phenone, 2-(2′-methacryloxy-5′-methylphenyl) benzotriazole, 2-(2′-hydroxy-5′-methacryoxyethylphenyl)-2H-benzotriazole, 2-[3′-tert-Butyl-2′-hydroxy-5′-(3″-methacryloyloxypropyl)phenyl]-5-chloro-benzotriazole, 2-(3′-tert-Butyl-5′-tert-Butyl-5′-[3″-dimethylvinyisilylpropoxy)-2′-hydro-xyphenyl]-5-methoxybenzotriazole, 2-(3′-Allyl-2′-hydroxy-5′-methylphenyl) benzotriazole, 2-[3′-tert-Butyl-2′-hydroxy-5′-(3″-methacryloyloxypropoxy) phenyl]-5-methoxybenzotriazole, and 2-[3′-tert-Butyl-2′-hydroxy-5′-(3″-methacryloyloxypropoxy) phenyl]-5-chlorobenzotriazole wherein beta-(4-benzotriazoyl-3-hydroxyphenoxy)ethyl acrylate is the preferred ultraviolet light absorber.

(30) In one embodiment, the crosslinker may present from about 0.1% to about 10% by weight of the composition or from about 0.3% to about 10% by weight of the composition or from about 0.5% to about 10% by weight of the composition or from about 1% to about 10% by weight of the composition or from about 2% to about 10% by weight of the composition or from about 3% to about 10% by weight of the composition or from about 4% to about 10% by weight of the composition or from about 5% to about 10% by weight of the composition or from about 6% to about 10% by weight of the composition.

(31) In one embodiment, a crosslinker may present from about 1% to about 5% by weight of the composition or from about 2% to about 5% by weight of the composition or from about 3% to about 5% by weight of the composition or from about 4% to about 5% by weight of the composition.

(32) A UV absorber optionally may be added to the copolymer compositions. A novel, preferred, UV/blue light absorber, i.e., vinyl anthracene, may be added to the copolymer compositions. Conventional UV absorbers, such as a vinyl benzophenone or a vinyl benzotriazole, also may be used.

(33) In another embodiment, a UV absorber may present from about 0.1% to about 5% by weight of the composition or from about 0.2% to about 5% by weight of the composition or from about 0.4% to about 5% by weight of the composition or from about 0.6% to about 5% by weight of the composition or from about 0.8% to about 5% by weight of the composition or from about 1% to about 5% by weight of the composition or from about 1.5% to about 5% by weight of the composition or from about 2% to about 5% by weight of the composition or from about 3% to about 5% by weight of the composition or from about 4% to about 5% by weight of the composition.

(34) In yet another embodiment, the disclosure relates to a copolymer comprising: (a) a monomer containing an aromatic, carbazole and/or naphthyl moiety present from about 18% to about 28% by weight of the composition, (b) a first hydrophilic monomer present from about 39% to about 49% by weight of the composition, and (c) a second hydrophilic monomer present from about 23% to about 33% by weight of the composition.

(35) In yet another embodiment, the disclosure relates to a copolymer comprising: (a) a monomer containing an aromatic, carbazole and/or naphthyl moiety that is at least about 20% by weight of the copolymer (b) a first hydrophilic monomer that is at least about 40% by weight of the composition, and (c) a second hydrophilic monomer that is at least about 25% by weight of the composition.

(36) In still another embodiment, the disclosure relates to a copolymer comprising: (a) monomer containing an aromatic, carbazole and/or naphthyl moiety, including but not limited to vinyl carbazole, vinyl naphthalene, 2-vinyl naphthalene, and mixtures thereof; (b) a first hydrophilic monomer of 2-(2-ethoxyethoxy)ethyl acrylate, and (c) a second hydrophilic monomer of hydroxyl acrylate. In another embodiment, the copolymer further comprises a UV absorber. In still another embodiment, the copolymer comprise a crosslinker, including but not limited to ethylene glycol dimethacrylate. In still another embodiment, the copolymer comprises an initiator, including but not limited to AIBN.

(37) In still another embodiment, the disclosure relates to a copolymer comprising: (a) 2-vinyl naphthalene, (b) a first hydrophilic monomer that is 2-(2-ethoxyethoxy)ethyl acrylate, (c) a second hydrophilic monomer that is hydroxyl acrylate, (d) a UV absorber, (e) a crosslinker, and (f) an initiator.

(38) In still another embodiment, the disclosure relates to a copolymer comprising: (a) 2-vinyl naphthalene that is at least about 20% by weight of the composition, (b) a first hydrophilic monomer that is 2-(2-ethoxyethoxy)ethyl acrylate that is at least about 40% by weight of the composition, (c) a second hydrophilic monomer that is hydroxyl acrylate that is at least about 25% by weight of the composition, (d) a UV absorber that is at least about 0.5% by weight of the composition, (e) a crosslinker that is at least about 2.5% by weight of the composition, and (f) an initiator that is at least about 0.1% by weight of the composition.

(39) In still another embodiment, the disclosure relates to a copolymer comprising a monomer containing an aromatic, carbazole and/or naphthyl moiety, a first hydrophilic monomer, and a second monomer with a homopolymer having a glass transition temperature (Tg) less than 20° C.

(40) In yet another embodiment, the disclosure relates to a copolymer comprising: (a) a monomer containing an aromatic, carbazole and/or naphthyl moiety present from about 18% to about 28% by weight of the composition, (b) a first hydrophilic monomer present from about 39% to about 49% by weight of the composition, and (c) a second monomer with a homopolymer having a Tg less than 20° C. present from about 23% to about 33% by weight of the composition.

(41) In yet another embodiment, the disclosure relates to a copolymer comprising: (a) a monomer containing an aromatic, carbazole and/or naphthyl moiety that is at least about 20% by weight of the copolymer (b) a first hydrophilic monomer that is at least about 40% by weight of the composition, and (c) a second monomer with a homopolymer having a Tg less than 20° C. that is at least about 25% by weight of the composition.

(42) In one embodiment, a copolymer disclosed herein has an EWC in the range of about 5% to about 15% by weight. In one embodiment, a copolymer disclosed herein has an EWC in the range of about 3% to about 15% by weight. In another embodiment, a copolymer disclosed herein has an EWC in the range of about 4% to about 10% by weight. In another embodiment, a copolymer disclosed herein has an EWC in the range of about 5% to about 10% by weight.

(43) In one embodiment, a copolymer disclosed herein in a dry state has an EWC in the range of about 5% to about 15% by weight. In one embodiment, a copolymer disclosed herein in a dry state has an EWC in the range of about 3% to about 15% by weight. In another embodiment, a copolymer disclosed herein in a dry state has an EWC in the range of about 4% to about 10% by weight. In another embodiment, a copolymer disclosed herein in a dry state has an EWC in the range of about 5% to about 10% by weight.

(44) In another embodiment, the compositions and copolymers disclosed herein can be used to produce IOL's using techniques known in the art. In one embodiment, an IOL is produced using a lathe cutting method. In general, lathe cutting puts the lens material on a rotating mount, while machine cutting instruments sculpt away excess lens material to carve a precision-cut lens. The lenses are then polished and characterized.

(45) In another embodiment, the IOL is produced using a molding technique. In one embodiment, the comonomer solution is injected into a mold, cured at 60° C. for 4 hours and post cured at 100° C. for 4-8 hours. The IOL is demolded and extracted with an appropriate solvent.

(46) In another embodiment, injection molding for contact lenses is performed by heating the lens material to the point of melting, then injecting the liquid lens material into a pre-cut mold. Once the lens material dries, it will solidify in the form of the mold, giving precise shape to the lens. After the lens is removed, extra material may be removed, and the lens will be polished prior to being inspected for quality and characterization.

(47) TABLE-US-00001 TABLE 1 Examples 1-9: ΔD % Tg upon Example Monomer Concentration RI EWC ° C. hydration 1 PEA 70 1.5341 7 2 0.6 HEA 27 EGDM 3 2 PEMA 67 1.5401 6 12 0.6 HEA 30 EGDM 3 3 PEA 67 1.5441 8 16 0.8 HEMA 30 EGDM 3 4 BA 70 1.5241 9 10 1.0 HEA 27 EGDM 3 5 POEA 70 1.5201 10 19 1.0 HEMA 27 EGDM 3 6 BMA 60 1.5312 8 18 0.8 HEA 20 LM 17 EGDM 3 7 VC 27 1.5213 6 10 0.5 HEA 20 LM 50 EGDM 3 8 VC 30 1.5422 14 7 0.8 EHA 42 HEA 25 EGDM 3 9 VN 23.4 1.5332 8 −2 1.2 EEEA 44.2 HEA 28.0 EGDM 3.1 0.3% by weight of MEB was used in all copolymer compositions. PEA: 2-phenylethyl acrylate PEMA: 2-phenylethyl methacrylate POEA: Phenoxyethyl acrylate BA: Benzyl acrylate BMA: Benzyl methacrylate VC: vinyl carbazole VN: vinyl naphthalene EHA: 2-ethylhexylacrylate LM: Lauryl methacrylate HEMA: Hyroxyethylmethacrylate HEA: Hydroxyethylacrylate EEEA: 2-(2-ethoxyethoxy)ethyl acrylate EGDM: ethylene glycol dimethacrylates MEB: 2-(2′-Methacryloxy-5′ methylphenyl)benzotriazole

General Preparation Steps for Polymers of Table 1, Example 1-9

(48) The comonomers listed above were mixed in a glass flask using a magnetic stir bar for at least 30 minutes followed by sonication for the times indicated, and then stirring again for another 30 minutes.

(49) We found that sonicating for about 30 minutes at a power setting of 100% on a Branson 5510 provides optically clear materials with adequate optical and physical properties. The monomer solution is degassed with argon and poured in 6 in.×6 in. molds made from glass plates separated by a silicone gasket. The molds were kept at 60° C. for 6 hours and then post-cured in vacuo at 100° C. for 12 hours.

(50) The resulting copolymers are rigid enough to be machined at around room temperature. A unique aspect of the compositions, methods, and polymers disclosed herein is that the refractive index of these materials is so high that lenses are made thin enough to be folded without further processing or hydration.

(51) IOLs are machined from the copolymers to exact diopters. The IOLs are hydrated in distilled water for 3 hours at 50° C. and the diopter measured again in a hydrated state. The value obtained is the actual power of the lens that should be used for labeling purposes.

(52) Alternatively, a mathematical formula relating the diopter of a dry lens to that of the same lens hydrated may be developed from data such as that discussed below and used to label the IOLs.

(53) Empirical Estimation of In-Vivo Lens Diopter

(54) Unlike conventional hydrogel where lens hydration results into a significant decrease in diopter due to a decrease of RI of the polymer upon absorbing water, the lenses disclosed herein exhibit a relatively modest change in diopter upon hydration due to the small amount of water absorbed and a counterbalancing effect of the lens swelling and concomitant steepening of the radius of curvature. Lenses were lathe cut from sheets made from polymer compositions made according to the procedure described previously. Ten (10) lenses were selected for each composition. Table 2 below shows the diopter of 20 D lenses made from polymer examples 1-8 before and after hydration:

(55) TABLE-US-00002 TABLE 2 Examples 1-8: Diopter Diopter before after % hydration hydration Example RI EWC (D) SD* (D) SD 1 1.5341 7 20.0 0.1 20.6 0.3 2 1.5401 6 20.0 0.2 20.6 0.3 3 1.5441 8 20.0 0.1 20.8 0.2 4 1.5241 9 20.0 0.1 21.0 0.2 5 1.5201 10 20.0 0.2 21.0 0.1 6 1.5312 8 20.0 0.2 20.8 0.3 7 1.5213 6 20.0 0.2 20.5 0.2 8 1.5422 14 20.0 0.2 20.8 0.3 9 1.5332 7 20.0 0.2 21.2 0.3 *Standard deviation, of diopter measurement, n = 10.