by Matthew Kirk, M.D., Scripps Memorial Hospital La Jolla
It’s a fact: Aging isn’t kind to your eyes. Just when you get used to your reading glasses and bifocals, another potential vision problem may be waiting in the wings: cataracts.
A cataract affects the lens in your eye that focuses light on the retina. In a normal eye, light passes through the clear lens to the retina, where it becomes nerve signals that are sent to the brain to create visual images.
In order for the images to be clear, the lens must be clear. A cataract affects the proteins in the lens, causing it to cloud. As a result, you may experience decreased or blurry vision in one or both eyes. You may see glare or halos around lights, or have trouble with your night vision, especially while driving.
At first, a cataract may cloud only part of the lens. Over time, it may worsen, and vision loss gradually becomes more noticeable. The clear lens slowly becomes yellowed and vision can take on a brownish tint. Eventually, it may become difficult to distinguish between colors, especially blues and black.
What causes cataracts?
Age is the main factor behind most cataracts. They usually start to develop after age 50; by age 60, vision changes become more apparent. By age 80, more than half of all Americans have a cataract or have had cataract surgery. Other causes of cataracts, especially in younger patients, may include smoking, diabetes, uveitis (inflammation of the eye), trauma from an injury to the eye, or extensive exposure to UV rays from the sun. Family history may also play a role.
A cataract can develop in one eye or both, but it cannot spread from one eye to the other. If you develop cataracts in both eyes, chances are one eye will be more advanced.
How are cataracts treated?
The first step in treating cataracts is a thorough exam by an ophthalmologist to rule out other causes of decreased vision such as infection, macular degeneration, glaucoma, dry eyes or simply needing a new prescription for glasses or contact lenses.
Once a cataract has been confirmed, the ophthalmologist will grade its clarity to determine the proper course of action. Vision loss caused by cataracts in their earliest stages may be restored with eyeglasses, anti-glare sunglasses or improved lighting. If a cataract significantly impairs vision and interferes with daily activities such as driving or reading, surgery may be the only effective treatment.
Cataract surgery is an outpatient procedure that can be done in the operating room or surgery center under local anesthesia. During surgery, your ophthalmologist will remove the cloudy lens and replace it with a clear artificial lens called an intraocular lens. The procedure itself takes less than 30 minutes in most cases. If you have cataracts in both eyes, your ophthalmologist will typically do one eye first, and the other eye a few weeks later.
In recent years, there have been many technological advances in the intraocular lenses used in cataract surgery. Some of the newer lenses not only replace the old lens but can also reduce your need for reading glasses or help treat astigmatism, which is blurred vision caused by an irregularly shaped cornea.
Can cataracts be prevented?
While you can’t stop the effects of aging on your eyes, you can make lifestyle changes to help prevent cataracts caused by other factors. If you smoke, stop. Limit exposure to intense UV light with quality sunglasses.
Research suggests that good nutrition may also help reduce the risk of cataracts by protecting the lens from the damage caused by chronic exposure to UV light.
If you are age 50 or older, have your eyes examined at least once a year to check for signs of cataracts and other vision disorders. Early diagnosis and treatment may help preserve your vision.
Matthew Kirk, M.D. is an ophthalmologist with Scripps Memorial Hospital La Jolla. To learn more about cataracts or schedule an appointment, call 1-800-SCRIPPS (1-800-727-4777).