Lens, intraocular

Lens, intraocular: The clouded (cataractous) lens is best removed in its entirety by surgery and replaced with an intraocular lens (IOL) made of plastic, an operation that takes about an hour and usually does not need hospitalization. Cataract surgery was first done in India in the 5th century BC by a surgeon named Susruta who did a procedure called couching (or reclination) in which the clouded lens is pushed into the back of the eye, permitting better but by no means normal vision. Couching was still done in some countries until the mid-20th century. The first description of the cataract and its treatment in the West was in 29 AD by the Latin encyclopedist Celsus who performed the practice of needling (also called discission) of cataracts to break up the cataract into smaller particles to facilitate their absorption. Modern cataract surgery was first done in 1748 in France by Jacques Daviel, who removed the cataract from the lens. Today, the IOL is now usually the best type of cataract surgery.