Progressive spectacle lens with a variable refractive index, and method for designing and producing same

A product comprising:

• (i) a progressive power spectacle lens;
• (ii) a representation of the progressive power spectacle lens, the representation being stored on a non-transitory data medium;
• or
• (iii) the non-transitory data medium with a virtual representation of the progressive power spectacle lens,
• wherein the progressive power spectacle lens has:
• a front surface;
• a back surface;
• and
• a spatially varying refractive index,
• wherein at least one of the front surface or the back surface is configured as a progressive surface, wherein the progressive surface is a non-rotationally symmetrical surface having a continuous change in curvature over the entire surface or a part thereof,
• wherein the at least one of the front surface or the back surface configured as the progressive surface is a freeform surface,
• wherein the progressive power spectacle lens is made from a substrate having no individual layers, the substrate having at least one of a front surface coating on the front surface of the substrate or a back surface coating on the back surface of the substrate and including one or more individual layers,
• wherein a difference between a spherical equivalent measured at each point on the front surface of the progressive power spectacle lens with the front surface coating or the back surface coating and the spherical equivalent measured at each corresponding point on the front surface of a comparison progressive power spectacle lens without front surface coating and without back surface coating but with an identical substrate is less than a difference value selected from the group consisting of:
• (a) the difference value is less than 0.001 dpt,
• (b) the difference value is less than 0.002 dpt,
• (c) the difference value is less than 0.003 dpt, and
• (d) the difference value is less than 0.004 dpt.

A computer-implemented method for designing a progressive power spectacle lens with a front surface, a back surface, and a spatially varying refractive index, wherein at least one of the front surface or the back surface is configured as a progressive surface, the method comprising:

• calculating optical properties of the progressive power spectacle lens with ray tracing at a plurality of evaluation points at which visual rays pass through the progressive power spectacle lens;
• setting at least one intended optical property for the progressive power spectacle lens at a respective evaluation point,
• designing a representation of the progressive power spectacle lens by setting a local surface geometry of the progressive surface and a local refractive index of the progressive power spectacle lens in a respective visual beam path through the evaluation points;
• modifying the representation of the progressive power spectacle lens by approximating the at least one intended optical property of the progressive power spectacle lens, wherein the modifying includes modifying the representation of the local surface geometry of the progressive surface and the local refractive index of the progressive power spectacle lens in the respective visual beam path through the evaluation points, and wherein the at least one intended optical property includes an intended residual astigmatism of the progressive power spectacle lens;
• freely modifying the progressive surface in one spatial dimension or in two spatial dimensions;
• and
• freely modifying the local refractive index in at least two spatial dimensions.