Patent ID: 8044112

Claim:
A method of applying a hydrophilic coating onto a silicone hydrogel contact lens, comprising the steps of: (a) prior to contacting with a first coating solution for forming a prime coating which is not covalently attached to the contact lens, rinsing an uncoated contact lens with an organic solvent or a mixture of organic solvents at room temperature; (b) contacting the rinsed contact lens with the first coating solution having a temperature of from about 45° C. to about 95° C. to form the prime coating, wherein the first coating solution includes a polyanionic material having a first hydrophobic backbone and multiple ionizable pendant groups, wherein the first coating solution has a pH sufficient low to substantially prevent the ionizable groups from ionizing, wherein the prime coating comprises at least one layer of the polyanionic material; (c) rinsing the contact lens coated with the polyanionic material with water at room temperature; and (d) applying a top coating over the prime coating of the contact lens by contacting said contact lens, which is rinsed in step (c) with water at room temperature, with a second coating solution having a temperature of from about 45° C. to about 95° C. to form the hydrophilic coating on the contact lens, wherein the second coating solution contains a non-charged hydrophilic polymer having a second hydrophobic backbone, wherein the formed hydrophilic coating on the contact lens exhibits an increased hydrophilicity and a good durability characterized by surviving a digital rubbing test or 5 autoclave test.