A computer-implemented method for providing a modified lens shape for an uncut lens blank comprising the following steps: a) providing an original lens shape of an uncut lens blank having a front surface and a back surface, wherein the original lens shape comprises an original shape of the front surface and an original shape of the back surface of the uncut lens blank, such that the uncut lens blank satisfies predetermined optical properties, and wherein the front surface and the back surface both have their final shape prior to edging; b) determining a boundary line on the back surface, wherein a curvature profile of the original shape of the back surface is to be preserved within the boundary line, wherein the relative sagittal heights of the back surface are preserved within the boundary line and the curvature profile as such may be moved in a translatoric manner relative to the front surface; c) determining at least one carrier line on the back surface, and, for each carrier line, determining a boundary curvature of the back surface at the boundary line; d) determining, for each carrier line, a new curvature profile of the back surface along the respective carrier line between the boundary line and an outer edge of the uncut lens blank, wherein a curvature of the new curvature profile at the boundary line equals the boundary curvature and transitions monotonically and continuously towards the outer edge from the boundary curvature towards a predefined curvature value; e) determining a modified lens shape of the uncut lens blank, wherein the modified lens shape comprises the original shape of the front surface, and a modified shape of the back surface, wherein the modified shape of the back surface is determined by an optimization procedure based on the new curvature profile towards a target shape, and wherein the target shape includes the preserved curvature profile of the original lens shape within the boundary line and a thickness requirement for the outer edge of the uncut lens blank, wherein the target shape includes the curvature profile of the original lens shape of the back surface within the boundary line which curvature profile of the original lens shape is fixed during the optimization, the curvature profile of each carrier line outside the boundary line which curvature profile of each carrier line is fixed during the optimization, and the predefined curvature value for the back surface outside the boundary line. a) providing an original lens shape of an uncut lens blank having a front surface and a back surface, wherein the original lens shape comprises an original shape of the front surface and an original shape of the back surface of the uncut lens blank, such that the uncut lens blank satisfies predetermined optical properties, and wherein the front surface and the back surface both have their final shape prior to edging; b) determining a boundary line on the back surface, wherein a curvature profile of the original shape of the back surface is to be preserved within the boundary line, wherein the relative sagittal heights of the back surface are preserved within the boundary line and the curvature profile as such may be moved in a translatoric manner relative to the front surface; c) determining at least one carrier line on the back surface, and, for each carrier line, determining a boundary curvature of the back surface at the boundary line; d) determining, for each carrier line, a new curvature profile of the back surface along the respective carrier line between the boundary line and an outer edge of the uncut lens blank, wherein a curvature of the new curvature profile at the boundary line equals the boundary curvature and transitions monotonically and continuously towards the outer edge from the boundary curvature towards a predefined curvature value; e) determining a modified lens shape of the uncut lens blank, wherein the modified lens shape comprises the original shape of the front surface, and a modified shape of the back surface, wherein the modified shape of the back surface is determined by an optimization procedure based on the new curvature profile towards a target shape, and wherein the target shape includes the preserved curvature profile of the original lens shape within the boundary line and a thickness requirement for the outer edge of the uncut lens blank, wherein the target shape includes the curvature profile of the original lens shape of the back surface within the boundary line which curvature profile of the original lens shape is fixed during the optimization, the curvature profile of each carrier line outside the boundary line which curvature profile of each carrier line is fixed during the optimization, and the predefined curvature value for the back surface outside the boundary line.