A method for determining a contour of a frame groove in a rim of a spectacle frame includes illuminating the rim, capturing a plurality of images of the illuminated rim from different predetermined perspectives, evaluating the captured images, and determining a spatial curve of the frame groove based on the evaluated images. The rim is illuminated along the entire circumference of the rim by directed illumination. Moreover, the evaluation of the captured images includes assigning each portion contained in the captured images to a respective surface element of the frame groove on the basis of at least one of the following properties: shadowing of the respective portion, brightness of the respective portion and phase angle of the illumination of the respective portion. Moreover, an apparatus, a computer program, a method for grinding a spectacle lens, and a computer-implemented method for determining a geometry of a spectacle lens are disclosed.