A semi-finished ophthalmic lens for formation of a plurality of different finished ophthalmic lenses requiring reduced amounts of lens material to be removed for formation of the finished ophthalmic lenses and reduced rates of departure of a surfacing tool and methods of making the same.

A semi-finished lens includes an object-side surface and an eyeball-side surface and is to be an eyeglass lens completed by processing the eyeball-side surface. The object-side surface of the semi-finished lens includes an optical region and a non-optical region.

The object of the invention relates to a method of designing a colour filter for modifying human colour vision by defining the spectral transmission function of the colour filter such as to maximise colour discrimination between more than one element, colour sample, of a colour sample set when a targeted human eye, the colour vision of which is to be modified, is viewing the colour sample set with the colour filter, and at the same time such as to minimise the difference between the colour identification of the colour samples by the targeted eye and a reference eye having a reference colour vision. The object of the invention also relates to such a colour filter, such a colour filter set, and the use of such colour filter and a method for modifying human colour vision.

The supply systems for providing spectacle ophthalmic lenses have improved efficacy, in particular with respect to lens blank picking performance and/or lens manufacturing performance.

A finished lens with a predetermined shape, including one front face, one back face and a perimeter corresponding to the shape, including a prescription part on the lens that together with the front face fulfills prescription data of a wearer and a peripheral part on the lens, the prescription part being delimited by a thickness curve and the peripheral part extending from the thickness curve towards an outer edge of the lens, the thickness curve corresponding to a value of thickness less than or equal to a predetermined thickness requirement.

A method, implemented by a computer, for determining a lens design of an optical lens adapted to a wearer, the method including: providing a wearer parameter; a lens design determining, during which the lens design of the optical lens adapted to the wearer is determined based at least on the wearer parameters. The wearer parameters include at least optical distortion sensitivity data representative of sensitivity of the wearer to optical distortions.

A progressive power lens group includes a plurality of progressive power lenses including a near region for seeing an object at a near distance, a specific region for seeing an object at a far distance in relation to the near distance, and an intermediate region provided as a region between the specific region and the near region and having a power progressing from the specific region toward the near region, in which a near power at the near region is common in the plurality of progressive power lenses and a power corresponding to a predetermined common target distance which is a distance between the near distance and the far distance is provided at a predetermined part of the intermediate region.

A method for determining a semi-finished lens blank, including the steps of: determining, for a given material, a set of faces (S.sub.1, S.sub.2, . . . S.sub.n) to be defined for a line of ophthalmic lenses, each face (Si, Sj) being defined for a corresponding subset (SEi, SEj) of wearer data and/or frame data; determining, for each face (Si, Sj), a minimum thickness requirement (EnvSi, EnvSj) necessary to produce all the lenses of the corresponding subset (SEi, SEj); determining combinations of two faces (Si, Sj) to be paired; defining a “double-faced” semi-finished lens blank (SF(ij)) consisting of two paired defined faces (Si and Sj) and including the minimum thickness requirements (EnvSi and EnvSj) respectively determined for the faces, in a manner that allows producing all the lenses of the subsets (SEi and SEj) corresponding to said faces.

A method includes: providing lens blank data relating to the first, second and peripheral blank surfaces of the lens blank; providing optical lens data relating to the first, second and peripheral optical surfaces of the optical lens; virtually positioning the optical lens in the lens blank in a position so that at least one of the first optical surface or the second optical surface is included within the lens blank; evaluating a manufacturing prism cost function, the machining prism cost function corresponding to a weighed sum of the first manufacturing prism to be used when blocking the lens blank on the second surface to machine the first optical surface and of the second manufacturing prism to be used when blocking the lens blank on the first optical surface to machine the second optical surface. The positioning and evaluation steps are repeated so as to minimize the manufacturing prism cost function.

Disclosed is a method implemented by computer for determining a lens blank intended to be used for the manufacturing of a finished optical article. The method includes: —a virtual volume data determining step, during which virtual volume data are determined based at least on finished optical article data representative of the volume of the finished optical article and over-thickness data representative of over-thickness requirements, the virtual volume data are determined so that the virtual volume defined by the virtual volume data includes the volume of the finished optical article volume of the finished optical article and the over-thickness, —a lens blank determining step, during which a lens blank is determined based on the virtual volume data so as to include the virtual volume defined by the virtual volume data.