ABSTRACT
Vision is conceived as a tactile act, a palpation at a distance. This doctrine was developed in the Optics attributed to Euclid, found its nearly definitive formulation in the Optics attributed to Claudius Ptolemy, and dominated optics until the end of the 10th century and beyond. In this sense, optics is only geometry of perception, geometry of the gaze. It is this optics as geometry of the gaze that was transmitted into Arabic, along with most of the Greek and Hellenistic works on burning mirrors, optical meteorology, as well as the writings of philosophers and physicians. Even Ibn al-Haytham's optical work at first glance reveals two striking characteristics: extension and reform. Ibn Sahl had conceived and constituted an area of inquiry on burning instruments, and on dioptrics in addition. The point of view that he adopts when analyzing the phenomena of light is thus deliberately objective. Al-Kindi investigates the reflection of visual rays in various types of mirrors.
