A cataract is a clouding of the normally clear and transparent lens of the eye which is behind the pupil. When the lens becomes cloudy from age, injury or a birth defect, less focused light reaches the interior of the eye and vision gradually fails. Symptoms of cataracts can range from a barely noticeable loss of vision to virtual blindness.
The first symptom may be difficulty in performing routine tasks. Fuzzy or blurred vision, frequent changes in glasses, double vision, difficulty reading, poor night vision and glare and halos are common symptoms. When the cataracts become dense they are typically treated with surgery.