1. A method for identification of a given geometrical feature of an optical component, said method comprising: providing ( 32 ) the optical component ( 12 ), said optical component ( 12 ) selected from the group consisting of an ophthalmic lens and a semi-finished ophthalmic lens blank, and said optical component ( 12 ) composed of an organic material that emits light at an emission wavelength λ e when illuminated by an illumination wavelength λ i , said emission wavelength λ e being different from said illumination wavelength λ i ; illuminating ( 34 , 74 ) a surface ( 16 , 64 ) of the optical component with an incident light beam comprising at least light at the illumination wavelength but devoid from the light at the emission wavelength, said surface of the optical component being illuminated in an illumination direction with the incident light beam having the form of a sheet of light ( 56 ) substantially perpendicular to said surface of the optical component; collecting ( 36 , 76 ) light emitted at the emission wavelength by the illuminated surface of the optical component in a viewing direction to build an image of said surface, an angle between the illumination direction and the viewing direction being substantially between 5° and 90°; and processing said image by implementing computer means that applies metrics to compare the image with reference data that are specific to the given geometrical feature and produces and stores an identification output of said given geometrical feature that distinguishes between single vision lenses, bifocal lenses, trifocal lenses, and progressive addition lenses, wherein the processing of said image produces and stores a profile of a curve that is formed by an intersection of the sheet of light ( 56 ) and the illuminated surface of the optical component, the identification output of said given geometrical feature being produced from the profile of the curve, and the processing includes a calculation where the angle between the illumination and viewing directions is used to determine and store an exact value of at least one curvature radius of the produced profile of the curve.