| 主权项 |
1. A method implemented by computer means for providing to a wearer a customized progressive spectacle ophthalmic lens, said customized progressive spectacle ophthalmic lens being characterized by a set of optical data, wherein the method comprises:
a) providing the prescription data of the wearer, said prescription data comprising the sphere, cylinder, axis and addition (Add) prescribed values for said wearer, the wearing conditions for the wearer and the coma of the eye of the wearer; b) providing an initial optical data characterizing an initial progressive spectacle ophthalmic lens suitable to fulfil the requirements of the prescription data of the wearer, comprising a front surface and a back surface, a far vision point (x_VL,y_VL), a near vision point (x_VP,y_VP) and a meridian line representing the locus of mean points of a wearer when he is looking from far to near vision points; c) choosing a reference point (x_ref;y_ref) on the meridian line of the initial progressive spectacle ophthalmic lens; d) calculating the residual astigmatism of the initial progressive spectacle ophthalmic lens-eye system when the eye of the wearer is looking through the reference point, AR_ini(x_ref;y_ref), and the residual coma of the initial progressive spectacle ophthalmic lens-eye system when the eye of the wearer is looking through to the reference point, CR_ini(x_ref;y_ref); e) calculating a residual astigmatism target value for the progressive spectacle ophthalmic lens-eye system according to the reference point, AR_cib(x_ref;y_ref), thanks to following equation:
|AR_cib(x_ref;y_ref)|=S×|CR_ini(x_ref;y_ref)|, where 0.5≦S≦3 and where the values of AR_cib and CR_ini are in μm; f) calculating a correction function, SUR_cor(x;y), according to following steps:
(i) calculating AR_cor(x_ref;y_ref) according to following equation:
AR_cor(x_ref;y_ref)=AR_cib(x_ref;y_ref)−AR_ini(x_ref;y_ref)(ii) determining the radius, R_cor, of the toroidal surface having the said AR_cor(x_ref;y_ref) value at the point (x_ref;y_ref);a (iii) calculating SUR_cor(x;y) as being the points of said toroidal surface; g) calculating the customized optical data of the customized progressive spectacle ophthalmic lens by combining the correction function SUR_cor(x;y) to the front or to the back surface of initial optical data of the initial progressive spectacle ophthalmic lens; and wherein (x,y) are geometrical coordinates on a surface. |
