- 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)
Definition from: MeSH via Unified Medical Language System at the National Library of Medicine
- A clouding of the lens of the eye or its surrounding transparent membrane that obstructs the passage of light.
Definition from: Merriam-Webster's Medical Dictionary by Merriam-Webster Inc.
See also Understanding Medical Terminology.