LENSES FROM POLYMERIC DERIVATIVES OF ACRYLIC AND METHACRYLIC ACIDS

摘要

An object of the invention is a lens made from a non-hydrophilic acrylate or methacrylate polymer or copolymer and designated for application in a water medium inside a human eye or on its surface, i.e. an intraocular or contact lens, the originally non-hydrophilic surface layer of which was additionally hydrophilized by a partial hydrolysis or sulfonation in such a way, that the gradient of swelling results where the swelling continuously changes from its maximum on the very surface to the minimum in the non-swelling core unaffected by hydrophilization. In this way, light reflexes are removed or at least substantially reduced as well as the tendency to the surface growth of cells, irritation of neighbouring living tissues, and the formation of pressure necroses. Strong inorganic acids are most suitable for the surface hydrolysis. Their ability to swell and dissolve the employed acrylate polymer can be arbitrarily limited by dilution with water or by addition of well soluble salts. The thickness of hydrophilic layer is controlled in this way and also by the time of action. The surface hydrophilic layer may be crosslinked by simultaneous esterification with multifunctional alcohols, in the molecule of which remains after esterification at least one additional free hydrophilic group.