Molding of plastic spectacle lenses involves placing polished film into mold having required optical shape and bonding injected material to film

摘要

Spectacle lenses are made by placing a film (14) with the required surface finish in a mold (1,8) whose surfaces (4,12) are of a defined optical shape. Material is injected (28) into the mold and bonded to the film (14). An Independent claim is also included for a mold with a mold space (2) defined by surfaces (4,12) shaped according to the optical requirements of the lens. The first surface (4) has a perforation (5) with suction to draw the film (14) against it. The other surface (12) is formed by a membrane (10) whose curvature is adjusted by computer numerically controlled pins (24) and hydraulic pressure (20,21).