Patent attributes
A method and an apparatus for making visible a mark on a spectacle lens are disclosed. An illumination light beam is directed to the spectacle lens. The illumination light beam runs through the spectacle lens and, after having run through the spectacle lens, is reflected on a reflector configured as a retroreflector, then runs again through the spectacle lens, and is finally fed to a camera as an observation light beam. The reflector is moved. Further, a measurement light beam is directed to said spectacle lens and fed to a sensor for measuring a physical property of the spectacle lens. The measurement light beam is generated by a first light source and the illumination light beam is generated by a second light source. The first and the second light sources are physically distinct units.