Method for applying a coating onto a silicone hydrogel lens

A method for applying an ophthalmic product having a lubricous and wettable surface, comprising the steps of:

• (1) obtaining a silicone hydrogel contact lens,
• (2) placing the silicone hydrogel contact lens in a lens package containing an in-package-coating solution, wherein the in-package-coating solution comprises:
• (A) a polyanionic polymer having carboxyl groups,
• (B) at least one water-soluble and thermally-crosslinkable polymeric material comprising azetidinium groups,
• (C) at least one decomposable-at-autoclave material, wherein the in-package-coating solution has a pH of from about 1.0 to about 4.0, provided that the molar charge ratio of the polyanionic polymer and the water-soluble and thermal-crosslinkable polymeric material comprising azetidinium groups is from 1:100 to 100:1 and no precipitation is formed after mixings, wherein the polyanionic polymer attaching and forming at least one layer coating on the surface of the silicone hydrogel contact lens,
• (3) sealing the lens package with the contact lens and the in-package-coating solution having the pH of from about 1.0 to about 4.0,
• (4) autoclaving said package with the contact lens and the in-package-coating solution therein, thereby inducing crosslinking reaction between azetidinium groups of the water-soluble polymeric material and the carboxyl groups of the polyanionic polymer to form a crosslinked hydrophilic coating on the surface of the silicone hydrogel contact lens immersed in the in-package-coating solution, wherein the decomposable-at-autoclave material is hydrolyzed to increase the pH to 6.5 to 7.5, wherein the silicone hydrogel contact lens with the crosslinked hydrophilic coating thereon has a surface wettability characterized by having an averaged water contact angle of about 80 degrees or less and having improved lubricity as compared to uncoated lenses.