Ibn al-Haytham (965-1039 CE)

Abu Ali Muhammad Ibn al-Hasan Ibn al-Haytham, who was born in Basra, established the science of optics on new foundations and made it an organised discipline, for which he has been recognised as 'the father of optics'.

Ibn al-Haytham, known in the West as Alhazen, wrote numerous works on optics, but his major work was Kitab al-Manazir (Book of Optics). For over 500 years it remained the most important book on optics, and was translated into Latin and published in 1572 as Opticae Thesaurus.

It was most likely Ibn al-Haytham who discovered that light travels in straight lines, and that we see not by our eyes throwing light onto objects (as the Greeks had thought) but by the light reflecting off objects and entering our eye. In his book, he traces the functioning of the eye from the optic nerve originating in the brain to the eye itself, whose various parts, such as the conjunctiva, iris, cornea and lens he describes, pointing out the role of each in vision.

Ibn al-Haytham first devised the camera obscura ('al-bayt al-muzlim' in Arabic) or 'dark room' to illustrate the principal that rays of light, reflected from an illuminated object will pass through a tiny hole in a dark room and project an image of the object upside down on a white wall inside the room.