Ibn al-Haytham's Sketch of the Human Optical System. The oldest known drawing of the nervous system from Kitab al-Manazir of Ibn al-Haytham (from a manuscript held in the Süleymaniye Library, Istanbul), in which the eyes and optic nerves are illustrated. It shows a large nose at the bottom, eyes on both side and a hollow optic nerve that flows out of each one towards the back of the brain.