Patent ID: 11448796

Abstract:
The invention provides a method for determining whether a coated contact lens is completely covered by a covalently bonded coating, comprising the steps of (1) providing a coated polyvinylalcohol-based hydrogel contact lens wherein the polyvinylalcohol-based hydrogel lens body is composed of a polymer comprising at least 50% by mole of repeating units of vinyl alcohol, comprising a lubricious coating covalently attached to the lens body, (2) contacting the coated polyvinylalcohol-based hydrogel contact lens with an aqueous solution of a hydrophilic marker polymer for obtaining a treated contact lens, the hydrophilic marker polymer having reactive groups of in which R1 is methyl or ethyl and R2 is hydrogen or a C1-C4 alkyl and a dye tag moiety, at a pH of 4.0 or less for a contacting time to covalently attach the marker polymer onto the coated polyvinylalcohol-based hydrogel contact lens through 6-membered acetal rings, (3) determining whether marker polymer is (covalently) attached to the surface of the treated contact lens.