Sunglasses: Blocking Bad Light?
A lot of my friends are wearing sunglasses with pastel lenses -- yellow, pink, purple, and light blue. Some of them have UV stickers on them, but I find it hard to believe they protect your eyes. Am I wrong?
It's vital to choose sunglasses that block ultraviolet (UV) radiation. A number of studies have shown that over time, eyes exposed to sunlight become susceptible to disease. Make sure that any sunglasses you buy block at least 99 percent of UV rays -- it should say so on the label. (Labels that read "UV absorption up to 400nm" also block 99 percent or more of the harmful rays.) Adequate eye protection isn't necessarily expensive. You should be able to find sunglasses that block UV rays at all price levels.
Here's a useful guide to sunglass selection from the American Academy of Ophthalmology:
Infrared rays: Your eyes tolerate these rays efficiently, so you don't have to worry about protection against them.
Blue-blocking: Glasses that block blue light are usually amber-colored, but there's no medical consensus on whether or not blue light is harmful to eyes. However, amber-colored sunglasses can make distant objects more distinct in snow or haze. They are useful if you ski or spend a lot of time on the water. Make sure that these glasses also have UV protection.
Polarized: Polarized lenses reduce reflected glare when you're driving or fishing, but just because glasses are polarized doesn't mean they also block UV radiation.
Mirror-coated: Glasses coated with mirror finishes reduce the amount of visible light that enters your eyes, but not all of them block UV rays.
Wraparound: A good choice, these glasses protect your eyes from all angles. But do make sure the lenses block UV rays.
Gradient: These glasses are dark on top and light on the bottom. This type of shading helps cut overhead glare but allows you to see clearly from the bottom half. Don't wear them at the beach (or in the snow) -- the bottom section doesn't adequately reduce reflections off the ground. "Double-gradient" lenses are dark on the top and bottom but lighter in the middle. They may be helpful, but they're not recommended for driving because they dim the dashboard.
Before you buy, make sure that sunglasses fit comfortably. The Sunglass Association of America advises stepping outside, if possible, when you're trying on sunglasses -- to make sure you can see both light and dark areas well.
As far as tinted lenses go, they should be all right if they block UV rays adequately. Again, make sure they help you see better out of doors in bright sunlight (incidentally, a pink tint supposedly helps absorb light in foggy conditions). Your best choice for summer -- particularly those days at the beach -- are dark, wraparound lenses that block UV rays. For optimum eye protection, wear a hat with a brim, too. And don't forget the sunscreen.