Ibn al-Haytham put the eye in the dark room
In Cairo, a scholar asked how we see, then tested his answer with light, shutters and a darkened chamber.
Ibn al-Haytham wrote his Book of Optics in Cairo in the early eleventh century. Against older theories that the eye sends out rays, he argued that we see because light from objects enters the eye.1
The Arabic title is Kitab al-Manazir. It was translated into Latin as De aspectibus.
An argument made by experiment
He described light passing through a small opening into a dark room and forming an image on the far wall. Experiments like this, set up so others could repeat them, are a large part of why he is remembered.
Notes
- The Arabic title is Kitab al-Manazir. It was translated into Latin as De aspectibus. ↩