The present invention discloses methods for producing an optically clear, biocompatible and durable hydrophilic coating for contact lenses comprising the steps of first applying a polymer coating on the contact lenses by plasma polymerization of monomers containing ethylene glycol groups, followed by incubating the coated contact lenses at an elevated temperature to remove the volatile residual monomers trapped inside the coating. Advantageously, such methods produce an optically clear, biocompatible and durable hydrophilic surface for contact lenses in a dry, solvent-free process.