Definition of a cataract - Bệnh Viện Mắt Quốc Tế DND - 128 Bùi Thị Xuân HN

[:en]A cataract is a clouding of the eye’s natural lens, which lies behind the iris and the pupil. Cataracts are the most common cause of vision loss in people over age 40 and is the principal cause of blindness in the world.[:]