Vision quest

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What you need to know in order to preserve your precious sight

When I was in fourth grade, the teacher asked us to describe the color green to a blind person. The task was meant to illustrate the importance of creative description. But it proved a far more valuable lesson. It got me thinking about how priceless the gift of sight really is. Without it, a bright blue sky or the brilliant colors of a spectacular sunset would be mere words. And there are certain things even the most creative of descriptions cannot capture.

Sadly, millions of Americans suffer some degree of vision loss due to such common eye diseases as cataracts, glaucoma and macular degeneration. In fact, it's become almost an accepted tenet that our eyesight will deteriorate with age. In spite of the rapid technological advances in eye surgery, your best means of defense against vision loss are still regular eye exams, protective eye wear and, most important, proper nutrition.

"We now know that the risk of eye disease can be reduced by controlling one simple factor in our lives: nutrition," explains Richard Firshein, D.O., in his book The Nutraceutical Revolution (Putman, 1998). "New medical research indicates that specific antioxidants can lower the risk of eye disease and prevent macular degeneration, cataracts and glaucoma."

Macular Degeneration
The leading cause of vision loss in older Americans is macular degeneration. One in four people over 65 and one in three over 80 will suffer from some form of this disease, which damages the macula, the area located along the rear wall of the retina that's responsible for focusing on fine details. "This process slowly and progressively destroys sight in the center of the field of vision," Firshein says.

Some 90 percent of all cases are dry macular degeneration, characterized by the aging and thinning of the macula tissue. This occurs when small, yellowish deposits called drusen accumulate beneath the macula. These deposits gradually break down the light-sensing cells of the macula, causing distorted vision. The second, and much rarer form, wet macular degeneration, results from new blood vessels growing beneath the retina. These vessels leak small amounts of fluid and blood, which eventually causes a blind spot in the center field of vision. Symptoms of the disease most commonly appear in people over 60 but can begin as early as 40. They include blurry vision, the appearance of dark spots or the distortion of straight lines, like words on a page. Age, sun exposure, poor nutrition (which leads to free radical damage), heredity and smoking (both can reduce the amount of antioxidants in the eyes) are all risk factors.

"Anything that prevents clogging of your arteries may help to prevent macular degeneration," states Jeffrey Anshel, a California-based optometrist and author of Smart Medicine for Your Eyes (Avery, 1999). "Watching your dietary fat and cholesterol, exercising regularly, not smoking and watching your weight and blood pressure are wise moves."

Cataracts
By the time we reach our mid-70s, cataracts are often a fact of life. An average of 1.3 million cataract surgeries are performed annually, making it the most common surgery in the United States. Cataracts are characterized by a cloudy spot that forms over the eye lens, which prevents light from passing through and reaching the retina. "What clouds the eye lens is the damage from oxidation, a biochemical process set in motion when a highly reactive form of oxygen changes within our cells," says James Duke, Ph.D., author of The Green Pharmacy (Rodale, 1997). Studies have shown that the condition develops earlier among diabetics, smokers and those who take diuretics, steroids or tranquilizers. Living at high altitudes or spending a lot of time in the sun can also lead to an earlier onset of cataracts.

Normally cataracts begin to form between the ages of 52 and 64, but the actual symptoms--blurred vision, sensitivity to light and glare, increased near-sightedness and distorted images--don't typically show up until 65. By the time we reach our 70s and 80s, 50 percent of people with cataracts experience mild to severe vision loss as a result.

Glaucoma
Causing total blindness in nearly 80,000 people, glaucoma tops the list as the most common cause of preventable blindness in the United States among all age groups. Another 900,000 Americans have been diagnosed with it, and experts speculate 1 million more don't even know they have the condition. With 1 to 2 percent of those over 40 afflicted with glaucoma, it has the earliest rate of onset of the three major eye diseases.

Glaucoma is an increase of pressure inside the eye that causes damage to the optic nerve, the part of the eye that carries images to the brain. "Prolonged stress and inadequate diet over a long period of time are considered by many authorities to be the main causative factors in glaucoma," Anshel explains. At any given moment, there's a delicate balance of fluid circulating in your eyes that is continuously drained and replaced. If so much fluid is produced so that the eye can't drain it fast enough or the drainage mechanism breaks down, tissue fluid builds up and can force the lens forward, damaging the optic nerve or closing off the drainage tubes in the eye area. Either way, the result is increased pressure on the optic nerve, leading to damage and sometimes vision loss.

Typically, glaucoma causes symptoms like blurred vision, loss of peripheral vision, headaches, haloes around light, nausea and vomiting. For early detection, the American Academy of Ophthalmology in San Francisco recommends an eye exam every three to five years for those 39 years old or older. Get an exam every one to two years if you are over 50, have a family history of glaucoma, are African-American, have had a serious eye injury or are taking steroid medications--all of which are risk factors for the disease.

Sun Protection
While most of us wouldn't dream of going out in the sun without some kind of skin protection, few of us take the same precautions with our eyes. Yet several studies over the past decade have shown that spending long hours in sunlight without protection can dramatically increase the risk of eye disease. In one study conducted among 838 Chesapeake Bay fisherman, those who went without eye protection were three times more likely to develop cataracts than those who wore sunglasses or a brimmed hat.

The blame lies with ultraviolet rays. Over time, these powerful rays can literally burn eye tissue, leading to cataract formation and macular degeneration. There are two major types of UV rays. UV-A, the longer wavelength, tans and ages the skin. The shorter and more intense UV-B rays can blister and burn the skin, ultimately causing skin cancer in some cases. Both pose a risk for the eyes. While wearing a hat can reduce 50 percent of your exposure to these hazardous rays, only the proper pair of sunglasses can offer substantial protection. When buying sunglasses that the American Academy of Ophthalmology recommends, consider the following features.

Look for labels that say "blocks 99 percent of UV radiation" or "UV absorption up to 400nm." As well as "blocks 90 percent of infrared rays."
Polarized lenses have the added benefit of cutting reflected glare, but be sure they are also UV-protectant.
Wrap-around sunglasses are the best choice for completely blocking out harmful rays. Enough UV rays can enter around the edges of regular frames to reduce their benefit.
If you wear contacts, consider lenses with built-in UV protection, keeping in mind that they don't provide complete protection.
And remember that certain medications that make your skin more sensitive to sunlight also make your eyes more susceptible to sun damage. These drugs include tetracycline, doxycycline, allopurinol and phenothiazine.

Nutrition
"The brain and visual system use up to 25 percent of your nutritional intake," notes Anshel. While a well-balanced diet rich in antioxidants and minerals is essential, specific compounds can nourish the eyes and defend against vision loss.

We've heard about free radicals and the damage they cause in the body. The same goes for your eyes. That's why antioxidants, compounds that neutralize free radicals, are a vital component of eye health. While they won't cure eye diseases, they can help to delay onset and slow progression. Be sure to follow label dosages and don't self-prescribe large "therapeutic" amounts without consulting a knowledgeable health care practitioner.

Beta-carotene, a carotenoid with antioxidant properties that's found in vegetables like carrots and spinach and in fruits like apricots and cantaloupes, is one of the most widely recognized nutrients for eye health. It is converted into vitamin A, which is responsible for the transmission of light through the retina.

Other members of the carotenoid family that play a role in maintaining vision are lutein and zeaxanthin, two compounds that make up the yellow pigment in the retina. The presence of both has been shown to lead to lower levels of cataract formation and also protects the macula, helping to prevent degeneration.

Vitamins E and C, the mineral selenium and flavonoids like grape seed extract all help defend the eyes against free radical damage. Vitamin C also reduces eye pressure, making it especially helpful for those suffering from glaucoma. Also important for eye health are the B vitamins, vital in maintaining the nervous system. They should be taken together in a B-complex supplement or obtained from foods like whole grain cereals and brewer's yeast.

Zinc is the most common trace mineral in our bodies and is highly concentrated in the eye. Because many older people are zinc-deficient, Whether due to poor diets or low absorption, Anshel recommends taking a zinc supplement to replenish these stores. Zinc, however, can be toxic in large doses and can interfere with the actions of other trace minerals in the body.

Taking care of your eyes from the inside out will pay off in the long run. Firshein explains: "By taking a full complement of supplements, not to mention eating a healthful diet filled with leafy greens and juicy fruits, you can keep your eyes alert and strong enough to see into beautiful old age."

PHOTOS (COLOR): What you need to know in order to preserve your precious sight

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By Cristin Marandino

CRISTIN MARANDINO is managing editor of Vegetarian Times.

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