A: Jack, outdoor play is very healthy for young children, but it's also important to protect them from excessive sun exposure. Although most parents know that sun exposure can put their children at risk for sunburn and skin cancer, most don't know that it can also damage the eyes. Over time, exposure to the sun's ultraviolet (UV) radiation can cause cataracts (clouding of the lens), macular degeneration (damage to the retina) and skin cancer of the eyelids.

Sunglasses are very helpful for protecting children's eyes from the damage of UV rays. Here are some tips for selecting them.

• Buy sunglasses with a label certifying 99 to 100 percent UVA and UVB protection, or UV absorption up to 400nm, to ensure that the lenses block out the harmful rays. Dark lenses without UV protection can actually increase the damage to the eyes because they allow the pupils to dilate and let more dangerous rays hit the eyes.
• Select sunglasses that fit your child's active lifestyle. The glasses should resist impact, the lenses should be secure in the frames and the frames should be bendable and unbreakable. Polycarbonate lenses are the most impact resistant. Don't buy glass lenses unless required by your child's eye doctor.
• Have your child try on the glasses before buying them. The lenses should be large enough to shield his eyes from above, below and the sides. The frames should fit snugly against the bridge of his nose and above his ears so they won't fall off.
• Offer your child a selection of sunglasses that offer UV protection and fit well, and let him choose the color and style he likes best. Toddlers may want sunglasses in bright colors or animal shapes. Older children often prefer sunglasses in adult styles and colors.

Be a good role model by always using sun protection yourself. Teach your son to get in the habit of wearing sunglasses whenever going outdoors, on both sunny and cloudy days. Also have your son wear a hat with a brim to reduce the sun exposure to his eyes and face. In addition, play in the shade as much as possible, and try to avoid playing outdoors when the sun's rays are strongest, between 10 a.m. and 4 p.m. Also, remember to protect your son's skin by dressing him in long-sleeve shirts and using sun block with UVA and UVB protection and a minimum of SPF 15 on exposed skin.