Abstract: The proper individually given positions of dioptric portions on eyeglasses are determined by illuminating the eyes of an examinee by light rays emanating from a source situated at a close-range point to form light-reflection images of the source on the eyes, and by marking the course of each straight line connecting the light source with the respective image, at a distance from the respective eye corresponding to that of the respective eyeglass. The images are observed in a mirror which is planar and circular and surrounds the light source. The marking is achieved by adhering adhesive rings to respective transparent plates which are disposed between the light source and the respective eyes of the examinee at a distance from the latter which corresponds to that of the respective eyeglass. The dioptric portions are then formed on the respective eyeglasses in accordance with the markings on the transparent plates, and the eyeglasses are then mounted in a frame.