Progressive lens
AssigneeQ2100, Inc.
InventorsLoren C. Lossman, Larry H. Joel, James S. Carr
Life of this patent
Estimating the term…
Abstract
A progressive lens mold, a method of making a progressive lens mold, and progressive lenses made using such mold or method. Back faces of progressive molds are preferentially tapered at their edges to reduce prism effects in lenses made using such molds. The tapering is accomplished by removing more of the back face adjacent the near portion vision zone of the mold versus the back face adjacent to the far vision zone of the molds.
Claims18
A cast prescription plastic progressive eyeglass lens comprising a front face, a back face, a near vision correction zone, a far vision correction zone, and a vision transition zone between the near vision correction zone and the far vision correction zone, the lens being prescription-cast and having a vertical prism of less than about 1.5 prism diopter, and the lens having a from face cast from and shaped by the back face of a mold, the back face of the mold including (1) a centrally located concave surface having a near vision correction zone adapted to cast the near vision correction zone of the lens, a far vision correction zone adapted to cast the far vision correction zone of the lens, and a vision transition zone adapted to cast the vision transition zone of the lens, and (2) an annular surface which tapers at an angle from the edges of the back face of the mold to the edges of the concave surface in the back face of the mold.
Dependencies are inferred from the claim text.