A cataract is a clouding of the lens, usually naturally and related to aging. By age 80, more than half of Americans have a cataract or have had cataract surgery. Eyes develop cataracts independently. They cannot spread from one eye to another.
Most age-related cataracts are caused by protein clumping up and clouding the lens. When the clumping is small, the resulting change in vision may not be noticeable. When it becomes more widespread, vision becomes blurry and dull.
Another type of cataract is a gradual brownish tinting of the lens. Vision sharpness is not affected, but distinguishing colors, for example, blue from purple, may become difficult.
Age-related cataracts may appear in the eyes of 40-year-olds, but usually don't affect vision until after age 60. However, cataracts may have other causes besides age. Secondary cataracts occur as a result of other eye problems, like glaucoma, or health problems, such as diabetes. Traumatic cataracts come from eye injury, sometimes long after. Babies can be born with congenital cataracts, and some types of radiation can cause radiation cataracts.
- Blurry or discolored vision
- Glare or halos around bright lights
- Poor night vision
- Multiple images
Mild cataract symptoms may be improved with better lighting, anti-glare sunglasses, or corrective lenses. When a cataract interferes with normal activities, like driving or reading, the cloudy lens must be replaced with an artificial lens. Cataracts normally do not damage the eye.
- Heavy alcohol use
- Overexposure to sunlight
Cataracts are usually removed through a tiny incision. Through the incision, the surgeon inserts a small probe, which emits ultrasound that breaks up the lens, allowing its removal through the incision. The artificial lens is inserted through the same incision. It becomes a part of the eye.
The operation lasts about 20 minutes, and is nearly painless. The patient will be given IV sedation, and then their eye will be numbed with anesthetic eye drops. Patients are driven home the same day. If both eyes have cataracts, the two will be removed separately, a week or two apart.
Cataract removal is one of the most common surgeries performed in the United States. About 98% of people who have had cataract removal have better vision after the surgery.
It does take some time to adjust to the new lens and the brighter, more vivid images it transmits. Problems are rare, and include infection, bleeding, and inflammation. They are generally treated successfully.