Method For Providing An Optical System Of An Ophthalmic Spectacle Lens And Method For Manufacturing An Ophthalmic Spectacle Lens

摘要

Method for providing an optical system (OS) of an ophthalmic spectacle lens according to wearer's prescription data and wearer's optical needs with the provision that a wearer's optical need is not related to prescription data, where said optical system (OS) is defined by at least a front and a back surfaces (S1, S2) and their relative position, comprising the steps of: a) providing a semi-finished lens blank (SB); b) providing contour data (CD); c) choosing at least one localized optical feature (LOFi) suitable for the wearer's needs; d) positioning the contour data (CD)
wherein the semi-finished lens blank (SB) comprises: a first surface (SB1) having in each point a mean sphere value (SPHmean) and a cylinder value (CYL), a second unfinished surface, the first surface (SB1) comprising: a plurality of primary areas (Ai); border areas (Bi); and a secondary area.

主权项

1. A method for providing an optical system of an ophthalmic spectacle lens according to wearer's prescription data and wearer's optical needs with the provision that a wearer's optical need is not related to prescription data, where said optical system is defined by at least a front and a back surfaces and their relative position, comprising the steps of:
a) providing a semi-finished lens blank comprising a first surface having in each point a mean sphere value and a cylinder value, and a second unfinished surface, wherein the first surface of said blank comprises a plurality of areas of localized optical features; b) providing contour data defining the periphery of the front surface of the ophthalmic spectacle lens, where said contour data is inscribable within the first surface of the blank; c) choosing at least one localized optical feature suitable for the wearer's needs; d) positioning the contour data of step b) with relation to the first surface of the blank so that the front surface comprises a zone intersecting with the areas of the localized optical features chosen in step c); and e) defining the back surface and its relative position with the front surface by using the wearer's prescription data and the front surface;wherein the semi-finished lens blank comprises:
(i) a first surface having in each point a mean sphere value and a cylinder value, and (ii) a second unfinished surface,the first surface comprising:
(i) a plurality of primary areas, where the mean sphere value of each point of each primary area is equal to the area mean sphere value of the said primary area plus or minus 0.09 Dioptre, the area mean sphere value of at least one primary area being different from 0.25 Dioptre or more from the area mean sphere value of another primary area and the primary areas dimensions are such that a 5 mm diameter circle, preferably a 10 mm diameter circle, is inscribable within said primary area; (ii) border areas defined for each primary areas as the area that contacts and encompasses said primary area and where the mean sphere value of each point of said border areas is plus or minus 0.2 Dioptre from the area mean sphere value of the primary area; and (iii) a secondary area consisting of the points of the surface belonging to the convex hull of said primary areas devoid of the primary areas points and the border areas points where all the points of said secondary area have cylinder value superior to 0.1 dioptre, preferably superior to 0.25 Dioptre.