A cataract is a cloudy area in the lens of the eye. The lens is located inside the eye behind the iris (the colored part of the eye). The lens gets cloudier over time and causes vision problems.
Most cataracts happen naturally as people get older. What causes cataracts is not known, but many things may make cataracts more likely to form, such as:
Cataracts don't spread from one eye to the other, but many people have cataracts in both eyes. The cataract can be worse in one eye compared to the other.
The symptoms of a cataract include:
Cataracts do not usually cause complete blindness. However, it is possible to lose enough vision to make it hard to recognize objects.
The symptoms of a cataract develop slowly and are painless. The condition may go unnoticed and undiagnosed for a long time. It is often found during a routine eye exam.
An eye care provider will do a thorough exam. He or she will evaluate symptoms and determine the best course of treatment.
If a cataract is not interfering with your lifestyle or work, your provider may suggest changing your glasses or using brighter lights to help you read.
If the cataract is seriously affecting vision and cannot be helped with glasses or contact lenses, a surgeon may need to remove the lens. The surgeon may first use sound waves (ultrasound) to break up the lens so the pieces can then be removed through a narrow hollow suction tube. This part of the procedure is called phacoemulsification. In some cases, the lens is removed in one piece through a larger incision (nuclear expression). After the lens is removed the surgeon will put a new plastic lens in the eye.
Lasers are not used to remove cataracts. However, they may be used to open a cloudy membrane that may develop after cataract surgery.
With glasses, contact lenses, or surgery, you can regain vision if the rest of your eye is normal. Surgery to remove cataracts is usually more than 95% successful in restoring vision. Although a cataract cannot grow back, you may develop a cloudy membrane months to years later. This membrane can be removed using a laser.
You may reduce the risk of damaging your eyes and in turn reduce the risk of developing cataracts by wearing goggles or safety glasses at work or during activities where your eyes could be injured. Wearing glasses with a UV coating that protects your eyes from sunlight might prevent or delay some types of cataracts, but this is not proven.
Good blood sugar control can slow the progression of cataracts related to diabetes.
If you smoke, quit.
Dietary supplements and vitamins have not been proven to prevent cataracts.
If you are a woman and plan to have a baby, make sure you have had a German measles (rubella) shot at least 1 month before you try to become pregnant. If you have German measles while you are pregnant, your baby's eyes should be checked by an eye care professional soon after birth. A baby can develop cataracts if you had German measles or other kinds of infections while you were pregnant.