Oxygen permeable hard contact lens

Claim 1

A hard oxygen permeable contact lens of concavo-convex shape with the concave surface substantially conforming to the cornea of the eye, fabricated from a material formed by the copolymerization of (a) about 9 to 90% by weight of a polymerizable ethylenically unsaturated silicone ester having the following formula: ##STR20## wherein R is hydrogen or methyl; each R I individually is methyl or O--SiR 3 II ; each R II individually is methyl or phenyl; R III is methyl or phenyl, and R IV is methyl or phenyl or R III and R IV together form a bond with a bridging --O-- between the Si atom and R III to form a cyclic ring; each a, b, to form a cyclic ring; each a, b, and c individually is an integer of 0-3; p is an integer of 2-4; q is an integer of 0-10; n is an integer of 1-3; and r is an integer of 0-1; (b) about 5 to about 90% by weight of a polymerizable ethylenically unsaturated ester selected from the group of isobornyl methacrylate, isobornyl acrylate, isobornyl crotonate, dicyclopentadienyl methacrylate, dicyclopentadienyl acrylate, dicyclopentadienyl crotonate, isopinocamphyl methacrylate, isopinocamphyl acrylate, isopinocamphyl crotonate, t-butylcyclohexyl methacrylate, 5-butylcyclohexyl crotonate, 3,3,5-trimethylcyclohexyl methacrylate, 3,3,5-trimethylcyclohexyl acrylate, 3,3,5-trimethylcyclohexyl crotonate, neopentyl methacrylate, neopentyl acrylate, neopentyl crotonate, or mixtures thereof; (c) about 1 to 30% by weight of a hydrophilic monomer for wettability selected from the group of 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, acrylic acid, methacrylic acid, N-vinyl pyrrolidone, maleic anhydride, acrylamide, methacrylamide, N,N-dimethylacrylamide, glyceryl acrylate, glyceryl methacrylate, dimethylaminoethyl methacrylate, dimethylaminoethyl acrylate, polyethyleneglycol monoacrylates and polyethylene glycol monomethacrylates and their corresponding methyl ethers thereof, or mixtures thereof; (d) about 0-20% by weight of a cross-linking agent selected from the group of acrylate and methacrylate diesters of a compound selected from the group of dihydric alcohols, polyhydric alcohols, and phenols; methylene bisacrylamide; methylene bismethacrylamide; hexamethylene bisacrylamide; hexamethylene bismethacrylamide; divinyl esters; diallyl esters; or mixtures thereof; (e) about 0 to 20% by weight of a C 2 -C 20 straight or branched aliphatic monoester or diester of an ethylenically unsaturated carboxylic acid.