Monocentric corneal contact bifocal lens and method of manufacturing

Abstract From the Canadian patent

A one-piece bifocal contact lens of monocentric no-jump form, having a bifocal segment front surface portion with a smaller radius of curvature than that of the distant vision segment, wherein the front surface of the bifocal segment is tangent to the distant vision segment at a point or along a line or locus at or near the center of the segment line, and wherein the surface separating these segments lies along a lens meridian. A lens is also disclosed which has a novel modified form of truncation to provide a ledge for the lower lid to push the lens upward during reading, while at the same time permitting the secondary and peripheral curves to remain completely intact throughout the …