Shades of the Season
Sunglasses are more than a trendy fashion accessory. Besides making you look cool, they can protect your vision, help you see the world more clearly and even prevent lines and wrinkles around your eyes.
Although the human body miraculously replaces some damaged cells, the cells in the lens of the eye are never replaced. The sun emits two types of ultraviolet (UV) radiation UV-A and UV-B that are harmful not only to your skin but to your eyes. Excessive exposure to UV, especially from light reflected off sand, pavement, and water, can produce a burn on the surface of the eye. Like a sunburn on the skin, eye surface burns are painful but usually temporary. Long-term exposure to ultraviolet (UV) rays has been linked to a host of eye diseases, including macular degeneration; cataracts, or clouding of the lens; intraocular malignant melanoma (eye cancer); pterygium (tissue growth over the cornea); and photokeratitis (snow blindness).
“Anyone going out in the sun should protect their eyes. This is even more important if you are going to be on or near water, because water reflects the UV waves from the sun,” explains Dr. Chad East, optometrist with The Eye Clinic. With all of the options in protective eyewear styles and lenses, choosing a pair of sunglasses can become complicated. There are a number of lenses to consider when purchasing sunglasses:
- Polarizing lenses effectively reduce reflected glare, sunlight that bounces off smooth surfaces such as water or pavement. They are particularly useful for driving and boating.
- Photochromic lenses darken or lighten with the amount of light available.
- Mirror coatings reflect rather than absorb light and are primarily for wear under intense glare from snow or water.
Dr. East says that no matter what frame style or lens options you choose, you should insist that your sunglasses:
- block out 99 -100 percent of both UVA and UVB radiation
- screen out 25-90 percent of visible light (fashion tinted lenses usually do not meet this level)
- are perfectly matched in color and are free of distortion and imperfection
- have lenses that are gray, green or brown (gray is recommended)
“If you wear your sunglasses for hazardous sports or work, you should also choose polycarbonate lenses. This material provides the greatest available impact protection,” says Dr. East. “Wraparound sunglasses, which are shaped to keep light from shining around the frames can be worth considering, particularly if you spend a lot of time outdoors in bright sunlight.”
Dr. East says it’s important to remember that children and teenagers need protection, too. “They typically spend more time out of doors than adults and the lenses of their eyes are more transparent than those of adults and thus allow more UV radiation to reach the retina, the light sensitive layer at the back of the eyes. In addition, the effects of UV radiation on the eyes are cumulative, so it’s important to develop good protection habits early in life.”
It can be difficult to be certain the sunglasses you purchase are right for you because there are no federal sunglass regulations regarding UV radiation and visible light transmission levels, and lens quality. And, contrary to some manufacturer’s claims, not all lenses offer the same level of protection as others. Beware of deceptive labels! Some sunglasses sold at discount stores have a decal that claims 100% UV protection when in reality, they provide 100% of the FDA minimum recommended UV protection, which amounts to only 70% UV protection. “This is misleading,” says Dr. East, “but legal, unfortunately.”
Here are some ways to judge non-prescription sunglass quality:
- Check lenses to be sure the tint is uniform, not darker in one area than another (except gradient density lenses.
- Hold glasses at arm’s length and look through them at a straight object. Slowly move the lens across the object. If the edge of the object distorts, sways, curves or moves, the lens has imperfections.
- To be sure the lenses block enough light, try them on in front of a mirror. If you can see your eyes clearly through the lenses, they probably are not dark enough for glare reduction and comfort. This test does not apply to photochromic lenses.
“Sunglasses must be practical enough to protect your eyes, yet stylish enough to make you want to wear them,” adds Dr. East. “And adequate protection doesn’t have to cost more. Many inexpensive glasses provide equal or greater protection than a much more expensive pair. Expense may reflect other factors, such as optical quality, durability or fashion. The best sunglasses offer 100% UV absorption, the best optical quality and are the least likely to break.”
Call 1-800-826-5223, or stop by the nearest Optics Unlimited (located within each The Eye Clinic) or visit www.TheEyeClinic.net.