초록 ▼

A series of positive-power aspheric ophthalmic lenses for correction of hypermetropia is described. A lens in the series is aspherically corrected on its anterior surface within an optically active region of diameter D.sub.1 which is less than the lens diameter D. The optically active region is surr

A series of positive-power aspheric ophthalmic lenses for correction of hypermetropia is described. A lens in the series is aspherically corrected on its anterior surface within an optically active region of diameter D.sub.1 which is less than the lens diameter D. The optically active region is surrounded by a border region bounded by diameters D.sub.1 and D, which can be constant for all dioptric powers. The border region can be matched to the optically active region in the region of D.sub.1 such that the difference in anterior surface sag between D.sub.1 and D may be made to be a constant for all dioptric powers. Lenses produced using this invention are thinner and lighter than prior-art lenses. Other advantages include predictable and constant edge thickness at diameter D.sub.1, and enhanced productivity and yield in certain manufacturing processes.

대표청구항 ▼

[ What is claimed is:] [1.] An ophthalmic lens comprising a diameter D, an optically active central region of diameter D.sub.1, D.sub.1 being less than D, a border region between D.sub.1 and D, and a rotationally symmetric anterior surface, said rotationally symmetric anterior surface being convex t

[ What is claimed is:] [1.] An ophthalmic lens comprising a diameter D, an optically active central region of diameter D.sub.1, D.sub.1 being less than D, a border region between D.sub.1 and D, and a rotationally symmetric anterior surface, said rotationally symmetric anterior surface being convex throughout the optically active central region and being concave in at least part of the border region between D.sub.1 and D, wherein the lens has a thickness T.sub.1 at D.sub.1 and a thickness T at D, and T.sub.1 -T is between 0.0 mm and 0.2 mm, inclusive.