Alhazen is the Latinized name of Asan Ibn al-Haytham, an Arab mathematician, physicist, and astronomer.
He is considered the "father of modern optics" and made major contributions to the field of optics and visual perception.
Alhazen was a prolific writer, writing over 90 books in all.
He was credited with discovering a new branch of mathematics, analytic geometry.
He also worked to solve problems related to congruences and made significant contributions to astrophysics.
He attempted to measure the height of a homogeneous atmosphere, produced a detailed description of the earth, and made a mathematical model of planet motion without using Ptolemy's model.
His work influenced many notable scientists, including Galileo, Descartes, and Kepler.
Alhazen's theory of vision contradicted many of the assumptions of modern science.
Alhazen lived in Egypt during the Fatimid caliphate, descendants of the Prophet Muhammad.
He worked for al-Hakim in Cairo during the reign of al-Hakim, the caliph who was cruel, but was also a patron of science. Alhazen attempted to use his scientific knowledge to regulate the flooding of the Nile. After being convicted of this, Alhazen was put under house arrest.
He was released ten years later, after the death of the caliph.
Alhazen is best known for his Book of Optics, a seven-volume treatise on optics. Originally written in Arabic, the Optics was translated into Latin by an unknown scholar.