DEAR ABBY: While strolling on the beach recently, my wife and I noticed a young woman and her son wading. The boy was probably 3 or 4 years old. The mother was wearing sunglasses, but the child had none, and was squinting from the sun's glare.
On another occasion, we observed a mother pushing a stroller as she jogged. The infant in the stroller did not have his eyes protected from the sun and was squinting.
Abby, please urge parents to protect their children's eyesight with good sunglasses that block the UV rays. -- BILL FROM CORRALITOS, CALIF.
DEAR BILL: With pleasure. Almost all parents are aware that exposure to sunlight can damage a child's delicate skin. However, the danger of the sun's rays to the eyes has only recently been established. Studies have shown that permanent damage to the eyes can result from prolonged exposure without adequate protection.
According to Michael H. Marmor, M.D., professor of ophthalmology at Stanford University Medical Center: "Of greater concern than the acute damage caused by a day in the sun is the CUMULATIVE damage of REPEATED exposure that may contribute to chronic eye disease."
Long-term exposure affects not only the surface of the eye -- the cornea and conjunctiva -- but also the internal structures, the lens and the retina, resulting in cataracts and other conditions that may harm the child's vision later in life.
The most dangerous time for sun exposure is between 10 a.m. and 2 p.m. (or even longer in areas close to the equator). High altitudes, beaches, snow fields and bodies of water significantly increase ultraviolet (UV) exposure.
Parents should teach children to never look directly at the sun, even when they are wearing sunglasses. Sunglasses cannot protect a child's eyes from potentially serious injury caused by gazing directly at the sun.
The American Academy of Ophthalmology recommends sunglasses that screen out 99 percent to 100 percent of ultraviolet light (both UV-A and UV-B). They should carry one of the following labels: "Blocks 99 percent of ultraviolet rays," "UV absorption up to 40nm," "Special purpose," or "Meets ANSI UV requirements."
A common myth about sunglasses is that they have to be expensive to give adequate protection. Many $10 glasses may provide equal or greater protection than those costing $100.
Even infants' eyes should be protected. If necessary, the sunglasses can be secured with an elastic band.