Raphael’s patent optometer, c 1880
A raphael’s patent optometer, c 1880. This instrument consist a wooden box with removable lenses. At the front there is a three holes for the nose and the two eyes, and two holes for give the explanation which lens is situated for the eyes. The various powered lens are placed in a removable linen role. The lenses in the role are: 13-11-10-9-8-7-6-5-4-3-2-1-0-00-000-0000-48-42-40-36-30-24-20-18-16-15-14-13-12-11-10-9-8-7-6-5. When the text, raphael’s patent opsiometer could read, they had determined the required lenses. Dimensions box 21 x 24 x 32 cm high.