Most people know the harmful effects – such as premature aging and skin cancer – that ultraviolet (UV) rays can have on their skin. But many are not aware of the damage that UV rays can cause to the eyes. Possibly the most frightening aspect of UV damage is that it is cumulative; the negative effects may not present themselves until years later.
A recent survey sponsored by Transitions Optical Inc. revealed that although 82 percent of respondents knew that extended exposure to the sun could cause skin cancer, only 9 percent knew it could damage vision. Additionally, only one in six respondents said they wear sunglasses when they prepare for extended exposure to the sun and only one-third said they wear a hat.
“Most of us wouldn’t dream of staying outside in the sun without putting on sunscreen lotion,” said Daniel Garrett, senior vice president of Prevent Blindness America. “But we also have to remember to wear both UV-blocking lenses and a brimmed hat to protect our eyes as well.”
Protecting the Eyes
Eyes can be protected from UV rays in two important ways: By knowing the dangers of UV rays (see sidebar) and by wearing proper eye protection and hats that block UV rays.
UV rays can come from many directions. Although they radiate directly from the sun, they also are reflected from the ground, water, snow, sand, glass, road and other bright surfaces.
Prevent Blindness America counsels anyone working or playing outside to use eyewear that absorbs UV rays and to wear a brimmed hat or cap. A wide-brimmed hat or cap will block about half of UV rays, according to the experts at Prevent Blindness America. A brimmed hat or cap also can limit UV rays that hit the eyes from above or around glasses.
Eyewear that absorbs UV rays offers the most protection. All types of eyewear, including prescription and non-prescription glasses, contact lenses and lens implants, should absorb UV-A and UV-B rays. For UV protection in everyday eyewear, there are several options, including UV-blocking lens materials, coatings and photochromic lenses. UV protection does not cost a lot of money and does not get in the way of seeing clearly.
Sunglasses help in two important ways: They filter light and they protect the eyes from damaging UV rays. Mounting scientific evidence shows that long-term exposure to UV rays can lead to cataracts, macular degeneration or skin cancer around the eyelids. Encourage employees to choose sunglasses that:
- Reduce glare.
- Filter out 99 to 100 percent of UV rays.
- Protect the eyes.
- Are comfortable to wear.
- Do not distort colors.
Outdoor workers should be aware that if they are in locations where sun glare off of water or snow is an issue, they should wear sunglasses with a darker tint to block more light. The risk of eye damage from the sun is greater because of reflection off the water and snow.
Prevent Blindness America warns that sunglasses manufacturers do not always attach a tag or label stating the amount of UV radiation that sunglasses block. Only buy sunglasses that provide a clear statement about how much UV radiation is blocked. In addition, always read labels carefully and look for labels that clearly state the sunglasses block 99 to 100 percent of UV-A and UV-B rays.
Extended UV exposure has been linked to several types of eye damage. Laboratory studies have implicated UV radiation as a cause of cataract – a major cause of visual impairment and blindness worldwide – which is a cloudiness of the lens inside the eye that develops over a period of many years. Furthermore, studies have shown that certain types of cataract are associated with a history of higher ocular exposure to UV and especially UV-B radiation.
Other conditions caused or exacerbated by UV exposure include age-related macular degeneration (AMD), which is a leading cause of vision loss in the United States for people age 55 and older. Exposure to UV and intense violet/blue visible radiation is damaging to retinal tissue, and scientists have speculated that chronic UV or intense violet/blue light exposure may contribute to degenerative processes in the retina. Pterygium is a growth of tissue on the white of the eye that may extend onto the clear cornea where it can block vision. It can be removed surgically but often recurs, and can cause cosmetic concerns and vision loss if untreated. Finally, photokeratitis is, essentially, a reversible sunburn of the cornea resulting from excessive UV-B exposure. It can be extremely painful for 1 to 2 days and can result in temporary loss of vision. There is some indication that long-term exposure to UV-B can result in corneal and conjunctival degenerative changes.
In conjunction with UV Awareness Month in May, Prevent Blindness America launched a new, dedicated online resource to provide more information about how to protect the eyes from UV rays. The Web site –http://www.preventblindness.org/uv– offers a variety of tools and information on everything from risk factors to buying tips for sunglasses for adults and children. To learn more about the steps that can be taken to enhance and protect vision, visit http://www.HealthySightforLife.org.
Sidebar: What are the Dangers of UV rays?
There are two types of UV rays: UV-A and UV-B.
UV-A: UV-A can hurt your central vision. It can damage the macula, a part of the retina at the back of your eye.
UV-B: The front part of your eye (the cornea and the lens) absorbs most UV-B rays, but these rays may cause even more damage to your eyes than UV-A rays.
What eye problems can UV rays cause?
Over time, the effects of UV rays may help cause a number of eye problems.
Macular Degeneration: UV rays may lead to macular degeneration, a leading cause of vision loss for older Americans.
Cataract: UV rays, especially UV-B rays, may also cause some kinds of cataracts. A cataract is a clouding of the eye’s natural lens, the part of the eye that focuses the light we see.
Pterygium: Another UV-related problem is a growth called pterygium. This growth begins on the white of the eye and may involve the cornea. Eventually, the growth may block vision. It is more common in people who work outside in the sun and wind.
Skin Cancer: Skin cancer around the eyelids is also linked to prolonged UV exposure.
Corneal Sunburn: Corneal sunburn, called photokeratitis, is the result of high, short-term exposure to UV-B rays. Long hours at the beach or skiing without proper eye protection can cause this problem. It can be very painful and may cause temporary vision loss.