Surprising risk factors for vision loss

Vision loss threatens your independence. So it's essential to get regular comprehensive eye exams, particularly if you have certain vision loss risk factors. Some you might know about. Others might surprise you.

Well-known risk factors

Some of the most common risk factors for vision loss are diabetes, high blood pressure, and older age. Here's how they can affect your eyes.

Diabetes. People with diabetes have high blood sugar levels, which can damage blood vessels throughout the body. In the eyes, damaged blood vessels can leak, causing swelling or bleeding in the retina (light-sensitive tissue responsible for vision) or swelling in the central part of the retina (the macula). Both conditions (diabetic retinopathy and diabetic macular edema) can lead to vision loss.

Another vision risk of diabetes: "You're more prone to get cloudy eye lenses [cataracts] or lenses that swell and create vision loss that comes and goes," says Dr. Nimesh Patel, a vitreoretinal surgeon at Harvard-affiliated Massachusetts Eye and Ear.

High blood pressure or high cholesterol. High blood pressure — a measurement of 130/80 millimeters of mercury (mm Hg) or greater in adults — contributes to several eye problems. It can worsen leaky blood vessels in the eyes. It can also lead to blockages in eye veins or arteries, causing vision loss. "Higher pressure causes wear and tear on blood vessels in the eyes, which makes them more likely to form clots that block blood flow," Dr. Patel says. High levels of LDL (bad) cholesterol also can promote blood clots in the eyes.

Older age. Aging can trigger several changes in the eyes that increase the risk for certain conditions. The most common is age-related macular degeneration. "With aging, in some people, cells in the retina no longer function well. They allow deposits of substances that destroy the macula," Dr. Patel says. "The result is central vision loss."

Age also increases the risk for glaucoma — damage to the optic nerve that carries visual signals to the brain. Glaucoma is often caused by pressure that builds up when the eye's drainage system no longer works properly. The result is a loss of side vision.

Surprising risk factors

You might not know it, but certain lifestyle habits or health conditions can increase your risk for eye problems. Here are some examples.

Inactivity. Simply hanging out on your couch all the time can wind up hurting your eyes. That's because a sedentary lifestyle increases your risk for diabetes, high blood pressure, and high cholesterol. Those conditions, in turn, boost your risk for eye disease.

Psoriasis and other autoimmune disorders. Psoriasis causes raised plaques of white, scaling skin. It's an autoimmune condition — a chronic attack launched by the body's immune system. Sometimes psoriasis leads to an inflammatory eye condition called uveitis. Symptoms include redness, light sensitivity, pain with bright lights, and foggy vision. How can eye and skin problems be linked? "They're both the result of chronic inflammation in the body," Dr. Patel says. "Other autoimmune conditions, such as lupus or rheumatoid arthritis, also can cause uveitis."

Shingles. Shingles is a reactivation of the chickenpox virus (varicella-zoster) that's been dormant and hiding in the nerve cells. It can move through the nerves to the surface of the skin, causing painful blisters and potentially long-lasting pain. If the rash occurs on the forehead or nose, it can also affect the eye, causing problems in the front part of the eye (the cornea). "Eye symptoms such as vision loss or light sensitivity can develop weeks to months after getting shingles," Dr. Patel says.

Smoking. Smoking is a risk factor for many eye conditions. "It increases inflammation in the body and in the eye, and acts as an accelerant to any aging or degenerative process in the retina. Smokers are more likely to develop cataracts and macular degeneration. And smoking can worsen uveitis and diabetic retinopathy," Dr. Patel says.

What you should do

The American Academy of Ophthalmology recommends that you get a comprehensive dilated eye exam at age 40, even if you don't have any known eye disease. After that, you'll need a comprehensive eye exam every few years (depending on your health) until you're 65. Then you'll need a screening every year or two — more frequently if you have eye disease.

If you have any of the risk factors included in this article, you might need an eye exam sooner than the guidelines recommend.

In between eye exams, be proactive: try to get underlying conditions under control, exercise daily, eat a healthy diet, and conduct a simple vision test about once a month. "When you're watching TV, close one eye, and make sure the open eye is functioning as well as possible. Then repeat the test with the other eye," Dr. Patel says. "If you notice any changes, call your eye doctor to make an appointment."

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