Abstract: A series of back wafers for a laminated ophthalmic lens, wherein successive members of the series have a diopter difference in their concave curvature which is sufficiently small to enable a member of the series to be used in combination with any design and power of front wafer to produce a finished lens within the normal tolerance for such a lens. Preferably the diopter difference is 1/8 of a diopter. The invention also comprises a method of producing a laminated lens from the wafers. The series of back wafers enables the production of a finished lens within the normal tolerances for such lenses.
February 19, 1991
Date of Patent:
February 16, 1993
Pilkington Visioncare, Inc. (a CA. corp.)