The ancient Greeks thought our eyes emitted rays, like a laser,
which enabled us to see. The first person to realise that light
enters the eye, rather than leaving it, was the 10th-century Muslim
mathematician, astronomer and physicist Ibn al-Haitham. He invented
the first pin-hole camera after noticing the way light came through
a hole in window shutters. The smaller the hole, the better the
picture, he worked out, and set up the first Camera Obscura (from
the Arab word qamara for a dark or private room). He is also credited
with being the first man to shift physics from a philosophical
activity to an experimental one.
