Patent ID: 8388133

Claim:
A method for determining the shape of the bevel of an ophthalmic lens so as to have the ophthalmic lens fit a given spectacle frame, the method comprising the steps of: providing the three-dimensional (xi, yi, zi) internal profile of the groove of at least a rim of the spectacle frame expressed in the principal axes (Xf, Yf, Zf) of the spectacle frame and the length Pf of the periphery of the groove of the rim; providing the blocking point of the ophthalmic lens and the horizontal direction Xl of the ophthalmic lens; aligning the normal Zl to the surface of the ophthalmic lens at the blocking point with the Zf axe of the rim; aligning the horizontal direction Xl of the ophthalmic lens with the Xf axe of the rim; projecting the three-dimensional (xi, yi, zi) internal profile of the groove of the rim on the front face surface of the ophthalmic lens so as to obtain a three-dimension projected groove shape (xp, yp, zp); and modifying the coordinates of each point of the two-dimensional groove shape (xp, yp) based on two correction coefficients, Rx for the coordinate xp and Ry for the coordinate yp, with Rx+Ry=1 so as to have the length Pp of the three-dimensional groove projected shape (xp, yp, zp) equal to the length Pf of the periphery of the internal profile of the groove of the rim so as to obtain the shape of the bevel of the ophthalmic lens.