How to Tell If Your Sunglasses Really Are Blocking Harmful Rays, According to an Ophthalmologist
When you shop for new sunglasses, the top priority is that the pair flatters your face, right? Not exactly. While the size, shape, and style of your glasses should factor into your choice, the most important consideration is that the glasses offer complete protection from the sun's harmful ultraviolet, or UV, rays. "UV protection is very important in keeping the surface of the eye as well as the retina from getting damaged," says Michelle Andreoli, M.D., clinical spokesperson for the American Academy of Ophthalmology (AAO). "Sunglasses with UV protection should be worn anytime you're outside, even when it's cloudy."
Interested to learn more? See how you can tell if the sunglasses you already own (or plan to buy in-store) offer this vital protection.
Look at the label.
Every pair of sunglasses sold by a retailer—whether they're from a drugstore or high-end boutique, made of plastic or glass—should have a tag or sticker on the lenses that says they provide "100-percent UV protection." If there's no such information on the glasses, Dr. Andreoli recommends either look for another pair or get a simple test done that will quickly determine the glasses' UV protection.
Choose the right frame and lens for sunglasses.
For optimal UV protection, wear oversized frames or, even better, the wraparound style, which protects against UV rays coming in from the sides. And while sunglasses with black or brown lenses may seem more effective in blocking harmful rays than light colors, like amber or pink, the color of the lens is irrelevant to UV level. "Dark tints can be helpful when the sunlight is very bright, like at the beach," says Dr. Andreoli, but they do not offer UV protection. "Amber tints block out blue light, which helps with contrast," she says, adding that "yellow or orange tints can be helpful to amplify the contrast of a view, for example, in the rain or at dawn and dusk," but they too must be labeled (or tested) "100 percent UV protection" to be the real thing.
Polarized lenses are a specialty type that offers no advantage in UV protection, adds Dr. Andreoli. "Polarized lenses are designed to diminish glare, not UV radiation," she explains. "They are not for protection, they are for comfort."
If you're still unsure, have them tested.
It's easy to find out if your sunglasses have what's needed. According to the AAO, you can take them to any optical shop that has a UV light meter to check the level of protection. Most opticians will test them for free; the whole process should take less than 30 seconds.
And while there's no general consensus on how long UV protection lasts in a pair of sunglasses, but there is some evidence that, over time, the effect can wear out, says Dr. Andreoli. To be safe, get your sunglasses tested. "UV sunglasses may need to be replaced every few years for full protection."