If your child spends a lot of time outdoors — and most do — buy her a good pair of sunglasses.

Long hours in the sun without eye protection raise your child’s odds of vision problems later in life. Those problems include cataracts, surface lumps and macular degeneration.

What's more, the lens in a child's eye is clearer than an adult's. That makes the child's eye more vulnerable to ultraviolet (UV) radiation.

Sunglasses can shield your child's eyes from two types of UV radiation. "Choose sunglasses that protect your child’s eyes from 99 to 100 percent of both UVA and UVB radiation," says Dr. David Weakley, an ophthalmologist on the medical staff at Children's Medical Center of Dallas.

The more ultraviolet light you can keep out of the eyes, Dr. Weakley says, the greater the safety. If you can see your child's eyes clearly through the lenses, they probably aren't dark enough to provide good protection. Still, the darkest lenses don't ensure the best protection.

Heed labels, not prices. Costly sunglasses aren't necessarily better. Labels to look for: "Blocks 99 percent of ultraviolet rays," "UV absorption up to 400 nm," or "Meets ANSI UV requirements."
Check the lenses for distortion. Look through the glasses at arm's length and move them slowly across, up and down over a square pattern, such as floor tile. If the lines sway or wiggle, the lenses aren't perfect.
Buy wrap-around sunglasses with large lenses that fit close to the eye. This helps block sun from all directions.
Consider getting children who play sports special impact-resistant lenses made from polycarbonate plastic. Get them with a scratch-resistant coating.
Check the sunglasses from time to time to make sure they still fit and aren't damaged.
Get your child a wide-brimmed hat, which can reduce by half the UVB that reaches the eyes.
Let older kids help choose their sunglasses. They're more likely to wear them if they like them.
Tell your child not to look directly into the sun even when wearing sunglasses.
Wear sunglasses or a hat yourself. Children often follow parents' examples.