Method of manufacturing natural protein polymer contact lenses by

Abstract

In this method of manufacturing a flexible contact lens from a protein biological material, such as a protein polymer of the gelatine type or a type IV enriched human collagen, a hydrogel is first made by hydrating the protein biological material, in water or a physiological serum. A lens preform is then made from the hydrogel at a temperature between ambient temperature and the temperature at which the material liquefies, at which temperature the hydrogel has a paste-like consistency. This preform, which reproduces the shape of the finished lens with a greater or lesser degree of accuracy, but always with excess material, is then placed in a mold made from a low-loss dielectric material. The mold is in at least two parts which, when locked together, define a three-dimensional shape and a finished lens surface state. The hydrogel is then liquefied by irradiating the mold with an electromagnetic field at a frequency between 10.sup.8 and 10.sup.10 Hz. The parts of the mold are then locked together and the hydrogel is then gelified by cooling it in the mold. Finally, the hydrogel is then removed from the mold and is cross-linked by contact with a cross-linking agent such as an aldehyde. The resulting lenses have excellent shape and surface state characteristics and are very well tolerated biologically.