plasma surface treatment of contact lenses silicone hydrogel.

A method for treating the surface of a contact lens silicone hydrogel by a controlled manufacture comprising the following steps: (a) plasma treating the lens with an oxygen-containing atmosphere for more than 4 minutes per side, at a wattage of 100 to 1000 watts and a pressure of 0.1 to 1.0 Torr (13.3 to 133 N / m2) to produce a coating containing silicate, (b) hydrating the lens by immersing the lens in an aqueous solution, so the amount of water absorbed by the lens is at least five percent by weight of the lens material, (c) subjecting the hydrated lens to heat sterilization, so that the lens heat sterilized has a coating containing silicate characterized by a configuration mosaic projecting plates surrounded by receding fissures when viewing an image of Atomic Force Microscopy (AFM) 50x50 microns (m) square, where the depth of the fissures is on average between about 100 and 50 0 angstroms (10 and 50nm) and the plate coverage is on average between 40 and 99 percent.