OPHTHALMIC LENS CONTAINING A FRESNEL SURFACE AND METHOD FOR MANUFACTURING SAME

摘要

A process for manufacturing an ophthalmic lens containing a Fresnel microstructured surface inside the lens. The Fresnel lens is injection molded with a mold insert having a heat conductivity lower than the thermoplastic material used to form the Fresnel lens. A second thermoplastic material is overmolded to the Fresnel lens to cover and protect the microstructured surface. The mold insert is made from Nickel or thermoplastic. The resulting lens includes two layers having different refractive indices. The Fresnel lens is made from polycarbonate while the overmold is made from PMMA or TPU.