A method of increasing the hydrophilicity of a polymer surface, such as a contact lens surface, includes exposing the polymer substrate to a first plasma under conditions selected to generate free radicals on the surface of the polymer substrate. The method also includes reacting an organic compound with the free radicals on the surface of the polymer substrate to thereby form an organic coating. The method further includes exposing the organic coating to a second plasma under conditions selected to oxidize the organic coating to thereby form a hydrophilic layer at the substrate surface. The hydrophilic layer can have a contact angle with respect to water that is less than about 50°.