A cataract is an eye disease in which the normally clear lens of the eye becomes cloudy or opaque, causing a decrease in vision. The lens is important for focusing light onto the back of the eye (the retina) so that images appear clear and without distortion, and the clouding of this lens during cataract formation distorts our vision. Cataracts are usually a very gradual process of normal aging but can occasionally develop rapidly. They commonly affect both eyes, but it is not uncommon for a cataract in one eye to advance more rapidly.
As we age, proteins in the lens begin to break down and the lens becomes cloudy. What the eye sees may appear blurry. This condition is known as a cataract.
Factors that may speed up cataract formation are:
- Eye inflammation
- Eye injury
- Family history of cataracts
- Long-term use of corticosteroids (taken by mouth) or certain other medications
- Radiation exposure
- Surgery for another eye problem
- Too much exposure to ultraviolet light (sunlight)
In majority of cases the cause is senile ( aging).
Adult cataracts develop slowly and painlessly. Vision in the affected eye or eyes slowly gets worse.
- Mild clouding of the lens often occurs after age 60, but it may not cause any vision problems.
- By age 75, most people have cataracts that affect their vision.
Visual problems may include the following changes:
- Being sensitive to glare
- Cloudy, fuzzy, foggy, or filmy vision
- Difficulty seeing at night or in dim light
- Double vision
- Loss of color intensity
- Problems seeing shapes against a background or the difference between shades of colors