OPHTHALMOLOGY

Subject: OPHTHALMOLOGY Sun May 04, 2008 11:07 am

OPHTHALMOLOGY
The doctors of Islam exhibited a high degree of proficiency and certainly were foremost in the treatment of eye diseases. Words such as retina and cataract are of Arabic origin. In ophthalmology and optics lbn al Haytham (965-1039 A.D.) known to the West as Alhazen wrote the Optical Thesaurus from which such worthies as Roger Bacon, Leonardo da Vinci and Johannes Kepler drew theories for their own writings. In his Thesaurus he showed that light falls on the retina in the same manner as it falls on a surface in a darkened room through a small aperture, thus conclusively proving that vision happens when light rays pass from objects towards the eye and not from the eye towards the objects as thought by the Greeks. He presents experiments for testing the angles of incidence and reflection, and a theoretical proposal for magnifying lens (made in Italy three centuries later). He also taught that the image made on the retina is conveyed along the optic nerve to the brain. Razi was the first to recognize the reaction of the pupil to light and Ibn Sina was the first to describe the exact number of extrinsic muscles of the eyeball, namely six. The greatest contribution of Islamic medicine in practical ophthalmology was in the matter of cataract. The most significant development in the extraction of cataract was developed by Ammar bin Ali of Mosul, who introduced a hollow metallic needle through the sclerotic and extracted the lens by suction. Europe rediscovered this in the nineteenth century.