Cataract
Cataract (vision), in medicine is an opaque condition of the lens of the eye or of its capsule. Its position behind the pupil readily distinguishes this condition from opacities of the cornea. Cataract may affect the lens alone (lenticular), or the front or back of the capsule of the lens (capsular), or both lens and capsule (capsulolenticular). Cataract is painless and unaccompanied by inflammation . It causes blindness by obstructing passage of light, but the patient can distinguish light from darkness. Traumatic cataract results from a perforating wound of the capsule of the lens. The entire lens becomes opaque, and a portion usually remains so; but at times, unless inflammation of other portions follows, the cloudiness entirely disappears. Congenital cataract is due to an intrauterine infection, chromosomal disorder, or metabolic disease that causes imperfect development or inflammation. Juvenile cataract may be hereditary. The lens is soft and white in both congenital and juven