System and process for making diffractive contact and intra-ocular lenses

Abstract From the Canadian patent

A diffractive bifocal eye lens an optical system, and processes for, fabrication of such lenses are disclosed. The optical system includes the following principal elements in optical alignment along an optical axis for accomplishing the indicated steps of the process: a laser for emission of ultraviolet light along the optical axis; a zone plate mask in the path of irradiation by the laser; and an imaging lens to project with radiation from the laser, an image of the mask on the concave inner surface of an eye lens mounted coincident with the image surface of the optical system thereby ablating the eye lens imagewise of the mask to generate a phase zone plate on the eye lens. The laser beam …