Most people know that excessive exposure to sunlight can cause serious damage to human skin. If this overexposure occurs in early childhood, the chances of skin cancer, including malignant melanoma, are significantly increased.

Most caregivers and parents recognize this potential problem and protect children’s skin with clothing and hats, sunscreen, and favoring shady areas outdoors. But did you know that overexposure to the sun’s rays also is potentially damaging to the eyes? Sheltering eyes from ultraviolet (UV) radiation is a critical part of a total sun protection program.

UV radiation is part of the spectrum of radiation emitted by the sun. UV rays are the sun’s “invisible” burning rays. There are three types of UV rays: UVA, UVB, and UVC.

UVC rays are blocked by the ozone layer and do not reach the earth’s surface, and do not pose a safety concern. However, overexposure to the other rays--UVA and UVB--can cause sunburn, premature aging of the skin, and the development of certain forms of skin cancer. UV radiation also may cause several different types of eye problems including cataracts, ocular melanoma, macular degeneration, and other forms of eye damage.

UV radiation can damage the retina, the back part of the eyeball that collects light rays and transmits images to the brain. This is particularly significant for infants and children under the age of 10; as the child gets older, cells are deposited in the lens (near the front of the eyeball) that increase the absorption of ultraviolet radiation, making damage to the retina less likely.

UV rays are most intense when the sun is at its highest in the sky (10 a.m.-3 p.m.) but it is important to protect children’s eyes whenever they are outside for a prolonged period. While UV exposure in the United States is greatest in the late spring and summer (May-August), it is important to be sun safe year-round. Sunlight reflected off water, snow, and pavement can be even more dangerous because it is intensified.

Ultraviolet rays also are present in fluorescent lighting, tanning bed lights, and high-intensity mercury-vapor lamps, which are often used for night sports. Teach children to avoid looking toward these sources of invisible, high-energy UV rays just as they should avoid looking directly at the sun.

Protecting Children’s Eyes

Children need outdoor play time, but they should practice sun safety. The eyelids provide some protection--that is why the eyes squint in bright sunlight. The pupil also contracts, decreasing the number of harmful rays that reach the lens and retina. Scheduling outdoor activities in early morning or late afternoon, providing shady play areas, and encouraging children to wear wide-brimmed hats will help protect both the eyes and the skin. However, the best protection for the eyes is a pair of sunglasses designed to block harmful UV rays.

Sunglasses protect the eyes from UV rays not because they are dark, but because of a chemical that is added during the lens-manufacturing process. Dark lenses without the proper UV-absorbing material allow the pupil to dilate, which can allow more light and UV radiation to enter the eye. Sunglasses with polarized or mirrored lenses do not provide protection unless they also contain UV-blocking material.

Sunglasses are regulated by the U.S. Food and Drug Administration (FDA) as medical devices, and the FDA requires that lenses absorb 99-100 percent of the UV radiation to adequately protect the eye. If the label says “99 percent UV protection,” you can be sure that the lenses block out enough of the sun’s harmful rays.

Sunglasses do not have to be expensive to offer the right kind of UV protection. Inexpensive mass-produced sunglasses that offer 99-100 percent UVA and UVB protection are fine; just be sure to check the label when you buy them. Avoid products that do not state exactly how much UV the product blocks.

Some prescription eyeglasses have special coatings that absorb UVA and UVB rays and provide adequate protection. If the child’s glasses do not have this coating, clip-on sunglasses can be used. Again, examine the labels on clip-on sunglasses carefully to make sure the lenses absorb that critical 99-100 percent of both types of rays.

Always keep sun safety in mind. Remember that sunglass lenses may be impact-resistant (as required by the FDA), but they are not shatterproof. Polycarbonate lenses are strong, durable, and impact-resistant. Special sports eye wear and sunglasses designed for rough activities are available as well.

The ‘best’ sunglasses are ones that children (and adults) will actually want to wear when outdoors. For infants, choose sunglasses that are comfortable and sturdy; remember, they will probably end up in the infant’s mouth.

Toddlers may want sunglasses in bright colors or animal shapes. However, most older children prefer sunglasses with styling that mimics that of adult sunglasses--cool, sophisticated and trendy--and in stylish colors. The color of the sunglass lenses is really a matter of personal preference. Some effect the way the eye sees colors, brightness, and contrast, and some do not.

Accessories also can make wearing sunglasses more appealing. By adding a cool visor to their attire, children’s eyes can be made even more sun safe! Let children decorate hard storage cases and teach them to care for their sunglasses.

Children should wear sunglasses when outside, even on cloudy days. But for some children, this is even more important than for others. Some medications can make children’s eyes more sensitive to sun. For example, some antibiotics may sensitize the child’s eyes (and skin) to UV radiation.

Some drugs used to control epilepsy can have the same effect. Be sure to ask parents or the children’s healthcare providers about the potential for problems with sunlight exposure if a child is taking medication. It also is important for children who have had cataract surgery to wear sunglasses, because the surgery reduces the lens’s ability to protect the inner eye from the UV radiation.

Prevention is the only effective way to prevent eye damage from sun exposure, so keep the 99-100 percent UV blockage in mind when planning outdoor activities.

Joe Knight, Family Practice Assistant and Writer, Fresno, CA

Prevent Blindness America, 211 W. Wacker Dr., Ste.1700, Chicago, Illinois 60606; www.preventblindness.org

Sun Safety Alliance, 413 N. Lee St., Alexandria, VA 22314; 703-837-4202; www.sunsafetyalliance.org

Sunglass Association of America, 390 N. Bridge St., LaBelle, FL 33935; www.sunglassassociation.com

All About Vision, www.allaboutvision.com/sunglasses/kids.htm

Kid’s Health, kidshealth.org/parent/firstaid_safe/outdoor/sun_safety.html

Healthy Childcare®: Sun Safety, www.healthychild.net/articles/sf11sun3.html

Safe Fun in the Sun, www.childhealthonline.org

SunWise Kids, www.epa.gov/sunwise/kids.html