CONTACT OR INTRAOCULAR LENS FROM LIGHTLY CROSSLINKED POLYMEROR COPOLYMER OF 2-HYDROXYETHYL METHACRYLATE AND A METHOD FOR THEIR PRODUCTION

摘要

A contact lens or intraocular lens made from a lightly crosslinked polymer of 2-hydroxyethyl methacrylate or from its copolymer, where the 2-hydroxyethyl methacrylate component prevails over the second nonhydrophilic component, has improved surface layer characteristics. The lens contains a hydrophilic, swellable, transparent surface layer and an inner part of lower swellability than the surface layer. The swellability of the surface layer decreases continuously from the surface towards the inner part to the swellability level of the inner part. The swellability of the surface layer may be up to 98% at the surface and the thickness of the surface layer may be as high as 100 .mu.m. The finally shaped lens is treated with an alkaline reacting solution of a salt, in which the lens does not swell. The lens is then freed of all soluble substances by washing.