What is (are) Cataract ?
A cataract is a clouding of the lens in your eye. It affects your vision. Cataracts are very common in older people. By age 80, more than half of all Americans either have a cataract or have had cataract surgery.    A cataract can occur in either or both eyes. It cannot spread from one eye to the other. Common symptoms are       - Blurry vision    - Colors that seem faded    - Glare - headlights, lamps or sunlight may seem too bright. You may also see a halo around lights.    - Not being able to see well at night    - Double vision     - Frequent prescription changes in your eye wear        Cataracts usually develop slowly. New glasses, brighter lighting, anti-glare sunglasses or magnifying lenses can help at first. Surgery is also an option. It involves removing the cloudy lens and replacing it with an artificial lens. Wearing sunglasses and a hat with a brim to block ultraviolet sunlight may help to delay cataracts.    NIH: National Eye Institute