Arab scholar from the medieval ages, Ibn al-Haytham (better known as Alhazen in the west), wrote his seven volume book on optics and other fields of study called the 'Book of Optics.' It disagreed with the then popular extra mission theory of vision, believed by Euclid, which stated that vision was a result of 'particles' leaving the eye and interacting with the object and refuted the theory by providing evidence and experiments to support its counterpart, the intromission theory. The translation of the book from Arabic to Latin is supposed to have laid the foundation for the invention and further development of eyeglasses in Italy in the later years. The image is from Wikimedia Commons and is available for public use.