Can Sunglasses Prevent Eye Disease? by Gary Heiting, OD

Sunglasses reduce glare, increase comfort and vision in bright sunlight, and Macular Degeneration are a popular fashion accessory. But can they prevent eye disease? Longer-wavelength UV rays (UVA) and Decades of research suggest sunglasses that effectively block both ultraviolet high-energy visible (HEV) rays both can (UV) and high-energy visible (HEV) rays can do just that. penetrate deep into the eye and affect the light-sensitive retina at the back of In particular, UV- and HEV-blocking sunglasses can prevent painful the eye. photokeratitis, and, when worn throughout life, may play a significant role in protecting the eyes from cataracts and age-related macular degeneration A number of studies have found UVA in later years. rays can cause damage to retinal cells that is consistent with changes that occur during age-related macular degeneration (AMD). Also, a recent European study found HEV radiation — especially when combined with low blood plasma levels of vitamin C and other antioxidants — was associated with the development of AMD.

Though multiple risk factors may be involved in the macular degeneration disease process, significant evidence exists that suggests wearing sunglasses that effectively block both UVA and Normal Vision Macular Degeneration Vision HEV rays throughout one’s lifetime may reduce the risk of debilitating vision loss from AMD later in life. Photokeratitis Portugal without sunglasses, Cooper ended up “blind for 36 hours,” he reported on Photokeratitis is a painful sunburn of the his talk show Anderson Live in December surface of the eye that causes serious 2012. “I had no idea you could do this,” discomfort and temporary vision loss. he said.

The cause of photokeratitis is It remains uncertain whether photokeratitis overexposure to ultraviolet radiation, causes long-term damage to the eye. Some and sunglasses that block 100 percent researchers believe repeated episodes of the sun’s UV rays can prevent this of photokeratitis may increase the risk painful and potentially dangerous eye of pterygium — an abnormal growth of An Ounce of Prevention… condition. conjunctiva that can invade the cornea Wearing sunglasses that block 100 and cause distorted vision, requiring percent of the sun’s UV rays and a Like sunburn of the skin, the symptoms surgical removal. significant amount of HEV radiation is of photokeratitis are delayed, occurring the best advice you can give patients 30 minutes to a couple hours after to protect their eyes from harmful sun overexposure to sunlight. Symptoms of Cataracts damage associated with photokeratitis, pain, watery eyes and blurred vision Though cataracts can have multiple cataracts and other eye diseases. typically last 24 to 72 hours. causes, cumulative exposure to the sun’s UV rays over one’s lifetime appears to be Use of UV- and HEV-blocking sunglasses Photokeratitis is also called “snow an important risk factor. should begin as early in life as possible blindness” because risk of the condition and continue throughout one’s lifetime is greatest at high altitudes on Also, researchers in Australia have found a for the best protection. snowfields, where the intensity of both strong positive association of sun exposure direct and reflected UV rays is highest. between the ages of 20 and 29 with the And remember, most UV and HEV But photokeratitis also can occur in formation of a specific type of clouding rays can penetrate clouds, so wearing warm climates, especially when on the of the lens later in life. Risk of cataract sunglasses on overcast days is just as water. development in this study was highest important as when in direct sunlight. among subjects with high sun exposure CNN journalist Anderson Cooper at younger ages, and the researchers Gary Heiting, OD, has more than 20 years recently discovered this first-hand. found use of UV-blocking sunglasses had experience as a clinical optometrist and is senior After spending two hours on a boat in a protective effect. editor of AllAboutVision.com.