Leah Smith visits her dermatologist to keep her skin looking as young as possible.

"Well, I think it's important to me like it is to any woman," says Smith.

She always uses sunscreen, but admits she's no expert on how to choose one.

"I’m not that educated about it honestly," says Smith.

Leah looks for a high "sun protection factor" or SPF.

"I usually use a 45," says Smith.

That's a good start. But SPF refers mostly to ultra-violet "B", or UVB rays. Those are the ones that give you a sunburn.

Doctor Jennifer Cather says there's more evidence than ever that ultra-violet "A" or UVA rays are just as much of a danger.

"They can penetrate into your skin and they have been linked with photo-aging wrinkles," says Dr. Cather.

The problem is, many sun worshipers and even sunscreen manufacturers pay more attention to UVB rays.

"I think everybody's more aware of the UVB rays because of the sunburn risk," says Dr. Cather.

To raise awareness about UVA, the food and drug administration has proposed a new labeling system like this one.

Sunscreens would still have an SPF number but also a separate UVA rating, from one to four stars.

Some manufacturers already promote their UVA and UVB protection. But you may start seeing the new rating system as soon as this summer.

There are also products on the market containing a powerful new sun-fighting chemical. One version is called helioplex.

"I want to remain looking as young as I can for as long as I can," says Smith.

Leah is living proof that shielding yourself from the sun can slow the hands of time.