Steven G Zantos

US Patent:

48969583, Jan 30, 1990

Filed:

Feb 18, 1988

Appl. No.:

7/157014

Inventors:

Keith S. Ames - Rochester NY
Steven G. Zantos - Fairport NY
Henry A. Knoll - Bath ME

International Classification:

G02C 704

US Classification:

351160R

Abstract:

A flexible contact lens (20) is disclosed as having a central power portion (24), a peripheral flange portion (27), and an externally concave transition portion (26) joining the central portion and the flange portion, whereby the flange portion extends outwardly from the central portion in the manner of a hat brim. The inner edge of the peripheral flange is thereby raised from the eye surface to facilitate movement of the lens over the limbal region of the eye. The extent of the peripheral flange forward from the eye surface promotes eyelid contact to enhance movement of the lens on the eye. In a second embodiment (40), the lens further includes an externally convex transition portion (45) joining the central power portion (44) and the externally concave transition portion (46) to facilitate lens handling. The invention also includes a method of producing such a flexible contact lens including the step of (a) forming a plastic mold on a tool which is a positive pattern of one surface of the desired lens, the resulting mold being a negative pattern of that surface, (b) placing unpolymerized fluid material in the mold, (c) rotating the mold to spread the fluid material at a desired thickness over the inner surface of the mold, (d) polymerizing the fluid material by appropriate means such as heat or ultra violet radiation, and (e) machining the opposite surface of the polymerized material to the desired lens configuration.