Partial or complete opacity of the crystalline lens of one or both eyes that decreases visual acuity and eventually results in blindness. Some cataracts appear in infancy or in childhood, but most develop in older individuals. (Sternberg Diagnostic Surgical Pathology, 3rd ed.)|Partial or complete opacity of the crystalline lens of one or both eyes that decreases visual acuity and eventually results in blindness. Some cataracts appear in infancy or in childhood, but most develop in older individuals. (Sternberg Diagnostic Surgical Pathology, 3rd ed.)|Partial or complete opacity on or in the lens or capsule of one or both eyes, impairing vision or causing blindness. The many kinds of cataract are classified by their morphology (size, shape, location) or etiology (cause and time of occurrence). (Dorland, 27th ed) (Experimental Factor Ontology, EFO_0001059)