Contact lens

Abstract

A contact lens formed of a composition comprising the reaction product of: A) at least 10 weight percent, based on the total composition weight excluding solvent, of at least one silicone-containing monomer of the formula I: where n is from 1 to 3, m is from 9 to 15, each a independently is C 1-4 alkyl, and each b independently is C 1-4 alkyl; B) at least 10 weight percent, based on the total composition weight excluding solvent, of 3-methacryloxypropyl tris(trimethylsiloxy)silane; C) N-vinyl pyrrolidone; and D) at least one other non-ionic hydrophilic monomer wherein the combined amount of A) and B) is at least 20 weight percent based on the total composition weight excluding solvent, and wherein the N-vinyl pyrrolidone (NVP) is present in such an amount that the reaction product comprises polyvinyl pyrrolidone (PVP) homopolymer.

1 - 15 . (canceled) 
     
     
         16 . A method of making a contact lens comprising the reaction product of at least one silicone-containing monomer and at least one hydrophilic monomer, wherein the method comprises the step of incorporating in the reaction mixture from 10 to 30 parts by weight, based on 100 parts by weight of the total amount of reactants excluding solvent, of a mixed solvent, wherein the solvent comprises at least one primary alcohol and at least one additional solvent which is more hydrophobic than the primary alcohol, and which is present in an amount of from 20 to 50 weight percent of the solvent. 
     
     
         17 . The method of  claim 16 , wherein the solvent is present in an amount of from 15 to 30 parts by weight. 
     
     
         18 . The method of  claim 16 , wherein the primary solvent is ethanol. 
     
     
         19 . The method of  claim 16 , wherein the solvent does not contain any secondary or tertiary alcohols. 
     
     
         20 . The method of  claim 16 , wherein the additional solvent is one or more of hexanol, octanol, decanol and ethyl acetate. 
     
     
         21 . The method of  claim 20 , wherein the solvent comprises ethanol and an additional solvent selected from hexanol, octanol, decanol and ethyl acetate. 
     
     
         22 . A method of making a contact lens comprising the reaction product of at least one silicone-containing monomer and at least one hydrophilic monomer, wherein the method comprises the step of incorporating in the reaction mixture from 10 to 30 parts by weight, based on 100 parts by weight of the total amount of reactants excluding solvent, of a mixed solvent, wherein the mixed solvent comprises ethanol and a co-solvent in an amount of at least 20 weight percent based on the total amount of solvent, wherein the co-solvent is at least one of hexanol, octanol, decanol and ethyl acetate. 
     
     
         22 . A method of making a contact lens comprising the reaction product of at least one silicone-containing monomer and at least one hydrophilic monomer, wherein the method comprises the step of incorporating in the reaction mixture from 15 to 30 weight percent, based on 100 weight percent of the reactants, of a mixed solvent, wherein the mixed solvent comprises ethanol and a co-solvent in an amount of at least 20 weight percent based on the total amount of solvent, wherein the co-solvent is at least one of hexanol, octanol, decanol and ethyl acetate.