Ibn al-Haytham (965–1039), best known as Alhazen, is one of the main figures of medieval Arabic science. He worked on mathematics, astronomy, optics, logic, philosophy and medicine, and, as a “modern” scientist, questioned previous theories, challenging, for instance, the Ptolemaic theory of vision. His works on light and optics, based on experimentation, established the basis for the development of Newton’s phys-ics. Due to his great influence on the development of human knowledge, especially on the fields related to light, Ibn al-Haytham must be remembered during the commemo-rations of the United Nations International Year of Light and Light-based Technologies 2015. [Contrib Sci 11(1): 95-102 (2015)]