Patent ID: 8883051

Claim:
A method for increasing the ion permeability of a silicone hydrogel contact lens, the method comprising: a. introducing into a mold a lens-forming material, wherein the lens-forming material comprises (i) at least one silicone-containing vinylic monomer or macromer, (ii) at least one hydrophilic vinylic monomer, (iii) two ion-permeability-enhancing vinylic monomers or macromers which are two polyethylene glycol methacrylates which have a polyethylene glycol chain having a molecular weight of 500 to 2,500 and are different from each other in molecular weight, wherein each of the two polyethylene glycol methacrylates is obtained by reacting a monofunctional terminated polyethylene glycol having one first functional group selected from the group consisting of amino, hydroxyl, acid chloride, and epoxy group at one terminus and a methoxy or ethoxy group at the other terminus of the monofunctional terminated polyethylene glycol, with a vinylic monomer having a second functional group coreactive with the first functional group and selected from the group consisting of isocyanate, amino, epoxy, hydroxyl, acid chloride, azlactone, and thiol group; and a crosslinking agent from about 0.05% to about 4% by weight b. curing the lens-forming material to produce the lens; and c. removing the lens from the mold, wherein the two polyethylene glycol methacrylates are present from about 0.5% to about 2.5% by weight and sufficient to provide the resultant lens with an increased ion permeability compared to a control lens while not significantly altering the water content and the oxygen permeability of the resultant lens as characterized by having changes in water content and oxygen permeability being less than about 8% relative to the control lens, wherein the control lens is produced from a control formulation having identical concentrations of all polymerizable components but without any polyethylene glycol methacrylate, wherein the lens has an ion permeability that is at least 40% greater than the control lens.