Finished ophthalmic lens and corresponding methods

摘要

Finished ophthalmic lens and corresponding methods. Finished ophthalmic lens having one concave face, one convex face; an outer perimeter with a thickness within a pre-established range; a central useful area that fulfills a pre-established ophthalmic prescription, which defines a machined surface, and which has a useful perimeter that coincides with a perimeter of a pre-established frame; and an outer transition area that joins the useful perimeter of the central useful area to the outer perimeter. A transition area includes a transition surface that extends from the machined surface and as far as the outer perimeter, is continuous and a derivative thereof is continuous on all points, including a joining line between the transition surface and the machined surface.

主权项

1. Method of machining an ophthalmic lens having one concave face and one convex face and an outer perimeter, where said outer perimeter has a thickness within a pre-established range, comprising:
(a) defining a central area with a perimeter that coincides with a perimeter of a pre-established frame and such that the central area is a progressive lens; (b) defining a surface to be machined on one of said concave and convex faces, so that said concave and convex faces, together, fulfil a pre-established ophthalmic prescription in said central area; (c) positioning said surface to be machined, arranged on the one of said concave and convex faces, with respect to the other of said concave and convex faces, so that said surface to be machined and the position of said surface to be machined with respect to the other of said concave and convex faces determines the thickness of the lens along said perimeter in said central area; (d) defining a transition area with a transition surface that extends between said perimeter of said central area and said outer perimeter, wherein the transition surface extends from the surface to be machined as far as said outer perimeter, and wherein said transition surface is continuous and a derivative thereof is continuous on all points, including a joining line between said transition surface and said surface to be machined; and (e) machining the transition surface in the surface to be machined of the ophthalmic lens.