PHOTOCHROMIC LENSES AND METHOD FOR MANUFACTURING

摘要

Methods for making optical quality plastics lenses with photochromic additiv es are described. According to a first embodiment of the invention, a casting resin containing photochromic additives is arranged bet ween a mold and a lens preform and then cured. According to a second embodiment of the invention, a casting resin substantially free of photochromic additives is arranged between a mold and a lens preform and then cured. The resin is then impregnated with photochromic addi tives. In a third embodiment a layering resin containing a photochromic additive is provided on the surface of a mold and cured to a gel state. Then, a casting resin that is substantially f ree of photochromic additives is arranged between the coated mold and a lens prefor m and cured. According to a fourth embodiment, a casting resin that is substantially free of photochromic additive is provided on the surface of a mold and cured to a gel state. Then, a cas ting resin containing photochromic additives is arranged between the coated mold and a lens preform and cured.