Abstract: A method for generating patterns progressively changing in configuration from circular through eliptical and oval and inclusive of rectilinear traces is effected by constraining a stylus to movement along mutually othogonal axes, by generating plural sets of stylus displacement forces and by applying such forces in combination to the stylus. The stylus displacement force sets vary with time in respective magnitudes and senses to compel stylus movement progressively in such circular, eliptical, oval and rectilinear patterns. In use of the pattern generating method for surfacing of an optical element, a surfacing tool in engagement with the optical element is displaced as the stylus and the optical element may itself be subjected to oscillatory movement.

Abstract: A method of making mold assemblies in which are cast polymerized synthetic resin, single vision and multi-focal plastic ophthalmic lenses. Molds are used to produce optical surfaces on the cast resin lenses. These are of glass which is optically surfaced and then assembled within a resilient carrier and supported frictionally in sealed engagement with the tubular resilient walls of the mold assembly carrier. The carrier is designed to provide for positioning the mold elements dimensionally so as to control concentricity, thickness and prism of the finished casting with no portion of the body of the carrier interlying the glass mold elements. Unrestricted shrinkage therefore is allowed to take place in thickness so as to allow full curing of the lens without premature mold separation. The mold assembly is sealed to provide a hermetic closure against leakage of contents or intrusion of air into the mold assembly during curing.