SPECTACLE LENS AND A METHOD FOR PRODUCING A SPECTACLE LENS

The present invention relates to a spectacle lens (110) for at least one eye (112) of a user (114), a method for producing a spectacle lens (110), and a computer program product comprising executable instructions for performing the method for producing the spectacle lens (110). The spectacle lens (110) comprises at least one permanent marking (120), wherein the at least one permanent marking (120) is or comprises at least one diffractive structure (124), wherein at least one diffractive pattern generated by illumination of the diffractive structure (124) is designated to be invisible upon a first kind of illumination (132) and designated to be visible only upon a second kind of illumination (144), wherein an incident light beam not comprising at least one wavelength in at least one of a near-infrared spectral region and a near-ultraviolet spectral region impinging on the lens body (116) outside the at least one diffractive pattern or on the least one diffractive pattern is transmitted without altering the spectral distribution of the light beam, whereas an incident light beam comprising at least one wavelength in at least one of a near-infrared spectral region and a near-ultraviolet spectral region which impinges on the least one diffractive pattern alters the spectral distribution of the light beam.The permanent markings (120) on the spectacle lens (110) is, on one hand, invisible to the user (114) or to a spectator looking at the user (114) wearing the at least one spectacle lens (110) without utilizing specially selected optical aids but, on the other hand, enables continued control of the at least one spectacle lens (110) in front of the at least one eye (112) of the user (114) by an optician or a specifically designated optical sensor.