Alhazen/Ibn al-Haytham
~965–1040 · Arab (born in Basra, lived in Egypt) · Islamic Golden Age
Known for: Father of optics who proved light enters the eye and pioneered the scientific method
Alhazen proved that vision works by light entering the eye—overturning 1,000 years of Greek optical theory that said eyes emit rays. His Book of Optics influenced Bacon, Kepler, and Descartes. He also demonstrated that light travels in straight lines and explained reflection and refraction.
He was imprisoned by the Fatimid Caliph al-Hakim and feigned madness for a decade to survive. He used his confinement productively—writing his greatest works.
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