|Alhazen+ (), frequently referred to as Ibn al-Haytham (Arabic: , Latinized as Alhazen or Alhacen; 965 – 1040), was an Arab scientist, polymath, mathematician, astronomer and philosopher who made significant contributions to the principles of optics, astronomy, mathematics, meteorology, visual perception and the scientific method.|
|Alhazen's problem+ Alhazen's work on catoptrics in Book V of the Book of Optics contains the important Islamic mathematical problem known as Alhazen's problem first formulated by Ptolemy in 150 AD.|
|Alhazen (crater)+ Alhazen is a lunar impact crater that lies near the eastern limb of the Moon's near side. Just to the south-southeast is the crater Hansen, and to the west is the Mare Crisium.|
was the first to make a systematic use of the method of varying the experimental conditions in a constant and uniform manner, in an experiment showing that the intensity of the light-spot formed by the projection of the moonlight+ through two small apertures+ onto a screen diminishes constantly as one of the apertures is gradually blocked up.G. J. Toomer expressed some skepticism regarding Schramm's view, arguing that caution is needed to avoid reading anachronistically particular passages in Alhazen's very large body of work, and while acknowledging Alhazen's importance in developing experimental techniques, argued that he should not be considered in isolation from other Islamic and ancient thinkers.