Color enhanced portrait of Abu Ali al-Hasan ibn al-Hasan ibn al-Haytham (Alhacen, Alhazen) (965-1040) was a Muslim, scientist and polymath described in various sources as either Arabic or Persian. He is frequently referred to as Ibn al-Haytham or al-Basri. Alhazen made significant contributions to the principles of optics, as well as to physics, astronomy, mathematics, ophthalmology, philosophy, visual perception, and to the scientific method. Alhazen wrote insightful commentaries on works by Aristotle, Ptolemy, and the Greek mathematician Euclid.