Cataracts

What is a cataract?
A cataract is a painless, cloudy area in the lens of the eye that blocks the passage of light to the retina. The retina is the nerve layer at the back of the eye. Cataracts usually cause vision problems.
See an illustration of a cataracts.
What causes cataracts?
A cataract occurs when the lens of the eye becomes cloudy. Aging and exposure to ultraviolet radiation can cause cataracts. Changes in the lens of the eye are often a normal part of the aging process and are common in older people, but they do not necessarily lead to cataracts.
Cataracts can also occur after an eye injury, as a result of eye disease, after the use of certain medications, or as a result of medical conditions such as diabetics.
Sometimes children are born with cataracts.
What are the symptoms of cataracts?
Not all cataracts affect vision. However, cataracts can cause cloudy, fuzzy, or foggy vision and glare from lamps or the sun. Driving at night may be difficult because of severe glare produced by headlights. You may need frequent changes to your eyeglasses prescription, and you may experience double vision in one eye or second sight, a temporary improvement in near vision in farsighted people.
How are cataracts diagnosed?
Cataracts are diagnosed with a physical exam and medical history. Further testing may be used to confirm the presence of a cataract or rule out other conditions that may be affecting vision.
How are cataracts treated?
Surgery is the only effective means of treating vision loss caused by cataracts.
Whether or not you need to have cataract surgery depends on the degree to which the cataract interferes with your daily activities. Surgery is almost always by choice (elective) and can be scheduled when it is convenient.
Cataracts in older adults do not always need to be removed. The vision loss that results from cataracts often develops slowly and may never become severe. Many people with cataracts adapt very well with the help of eyeglasses, contacts, and other vision aids and are able to avoid or delay surgery