Hydrophilic copolymers, the use thereof as biomedical materials and contact-optical articles produced therefrom

Abstract From the Canadian patent

Hydrophilic copolymers, the use thereof as biomedical materials and contact-optical articles produced therefrom A B S T R A C T, The invention relates to new cross-linked copolymers of N-vinyl pyrrolidone, N-alkyl-N-vinyl carboxylic acid amides, methacrylates and optionally further copolymerising monomers of a specific composition. The copolymers have a water absorption capacity of up to about 80% by weight, based on the hydrated state, and are suitable for the production of shaped articles which are in contact with living tissue in use. Examples include soft contact lenses and scleral lenses of high mechanical strength in, particular thin to very thin lenses for prolonged wear.