If you’re shopping for sunglasses, you probably go to the nearest drug store and pick up an inexpensive pair that fits OK and will keep you from squinting while you’re driving. But there is a better approach: Read the fine print on the packaging and find a pair of shades that will protect your eyes.
You should know by now the negative effects of sunlight on your unprotected skin: burning, wrinkling, premature aging and an increased risk of skin cancer. While your eyes may not show visible effects, they too are suffering damage from ultraviolet radiation every minute you’re outside in the sun.
About two decades ago, a large study involving Chesapeake Bay fisherman found that those with the greatest lifetime exposure to UV-B rays had an increased risk of cataracts severe enough to impair vision. A doubling of cumulative sun exposure translated to a 60 percent increased risk of a certain type of cataract.
A cataract is a clouding of the lens of the eye, a clumping of proteins that often occurs in response to aging, certain medications or injury to the eye. The result is a blurring of normal vision and difficulty seeing in the glare of bright lights.
In addition to the risk of cataracts, recent studies suggest an association between the high-energy visible radiation (HEV) of sunlight (known as blue light) and damage to the retina of the eye, including age-related macular degeneration. Macular degeneration is a major cause of blindness.
Just as you cover up your skin and wear sunscreen to protect your skin, so should you protect your eyes by wearing good quality sunglasses plus a wide brimmed hat any time you venture out into the sun for any extended period. Protection is needed winter or summer, even on cloudy days.
At a minimum, sunglasses should 1] block 99 to 100 percent of both UV-A and UV-B radiation, 2] absorb most HEV radiation, 3] reduce glare to a comfortable level, 4] fit tightly to the face, 5] be durable and 6] have lenses that will not distort images or colors.
Paying a higher price does not assure you of getting sunglasses that are safe for your eyes. The greatest protection comes from glasses that block virtually all UV-A and UV-B rays; if the label does not give you information about UV protection, skip them and move on.
The color and darkness of the lenses mean nothing in terms of protection from UV-A or UV-B radiation. A bronze, copper or reddish brown lens will be better at absorbing HEV or blue light. A darker lens will reduce glare, but unless UV protection is provided as well, your eyes may be in greater danger because the iris of the eye will be more dilated when it is shielded from glare.
Polarized lenses also work well for reducing reflected glare, such as sunlight bouncing off of water, snow or the hood of a car. They are useful for boating, fishing or driving. And they are particularly beneficial for persons with cataracts. They do not necessarily block ultraviolet rays, so be sure to read the label.
Visible light transmission (VLT) refers to the amount of light that is let through the lenses. Most dark sunglasses range from 15 to 20 percent VLT. If your eyes are sensitive or you spend a lot of time in high intensity light, you may want a darker lens such as one with a VLT of 8 to 12 percent. A lens that is too dark can be dangerous if you’re driving in a high intensity light situation and suddenly enter a darker one, such as a tunnel or a highly shaded area.
After age 50, your eyes tend to lose some of their light gathering ability. As a result, seniors may do better with a VLT of 25 to 30 percent or even higher. Some inexpensive plastic lenses can distort colors. Dark grey lenses are best for color identification. Green ones should definitely be avoided if you’re one of the 8 percent of males with color blindness. You may not be able to read traffic lights correctly.
Photochromatic or “transition” lenses are handy for persons who wear prescription eyeglasses all the time. They adjust automatically to different light conditions. The advantage is that you don’t need to carry a pair of prescription sunglasses.
Transition lenses take a while to adjust to changing conditions, and they don’t darken if you’re driving behind a windshield that blocks UV rays.
Finally, choose a pair of sunglasses that are appropriate for your activity level. Particularly if you are physically active, impact-resistant lenses made of polycarbonate or Trivex are less likely to shatter than plastic or glass.
The Long Term Care Authority of Enid Caregiver program makes no distinctions on the grounds of race, color, sex, age, national origin, religion or disability, and a portion of the project costs are met by state and federal Older American Act funds from the LTCA of Enid and OKDHS Aging Services.
Rupp is care coordinator for Long Term Care Authority of Enid Aging Services. Contact her at 237-2236.