Ask dermatologists to name the most treacherous skin villain of all, and the sun wins hands down. Sun damage, or photoaging, gives skin the texture of leather and can leave a formerly peaches and cream complexion riddled with wrinkles, spots, blotches, and broken blood vessels.

How can something that feels so good on our bare skin wreak so much destruction? In a word: radia tion.

The sun gives off two types of ultraviolet (UV) radiation: UVA, sometimes called tanning rays, and UVB, the so called burning rays. Until recently, UVA rays were thought to be harmless. In fact, UVA light is still used in tanning beds. But dermatologists now know that both UVA and UVB rays are equally destructive to the skin. Over the years, these rays slowly but steadily break down collagen and elastin, until one fine day presto! You've entered the Face Lift Zone.

The damage starts earlier than you may think. "Eighty percent of the sun damage takes place before the age of 20," says Rhoda S. Narins, M.D., clinical associate professor of dermatology at New York University Medical Center and a dermatologist in New York City and White Plains, New York.

Most vulnerable to photoaging are women with fair skin and light hair and eyes, and women who have grown up in high altitudes, where UV rays are at their most intense, says Dr. Franks. "I see women in their twenties who have grown up in Colorado or skiers who have spent years in high intensity sun, and they already have fine lines and wrinkles under their eyes."

Think your darker skin is immune to solar assault? Think again, says Dr. Franks. Even African Americans and olive skinned people of Mediterranean ancestry, whose skin contains more melanin than that of lighter skinned people, can sustain sun damage. "I've seen many olive skinned women who have extremely sundamaged skin," she says. "They seem to develop sunspots, or socalled liver spots, earlier."