Abstract: A method of data processing for providing an optical lens is disclosed, the method being implemented by computer means. The method comprises a determining step during which an association between an elements subset of an elements set and a properties collection is determined, the elements subset comprising at least two elements. And, the method comprises a storing step during which data related to the elements subset and the associated properties collection is stored, the elements subset related data describing the elements subset (SS1, SS2) from a list of primitive elements and a list of set operators.

Abstract: A method for determining a progressive ophthalmic lens comprising a near and a far vision area, a main meridian separating the lens into a nasal and a temporal area, the method comprising: determining a first and a second surface of the lens; determining the second surface to provide, in combination with the first surface, the vision correcting properties; determining a spherical area on the first surface of the lens having a constant sphere value and including a far vision diopter measurement position, wherein the far and a near vision diopter measurement position have substantially the same mean sphere value; and determining the first surface to reduce the lens distortion by defining a toric area extending outside the spherical area on the first surface in at least one of the nasal and the temporal area, wherein characteristics of the toric area are related to the lens astigmatism.

Abstract: 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.

Abstract: 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: providing a semi-finished lens blank (SB); (a) providing contour data (CD); choosing at least one localized optical feature (LOFi) suitable for the wearer's needs; positioning the contour data (CD) wherein the semi-finished lens blank 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 main area; t least a peripheral area (Ai).