Lenses that absorb and block UV are one of the strongest defenses against eye and eyelid damage, so it's best to wear sunglasses (prescription or non-prescription) year-round whenever you are out in the sun. UVA light can damage the eyes and the skin around them year-round, and even on overcast days, damaging amounts of UV can penetrate through clouds and haze. But remember, fashion and high price do not guarantee safety. For proper protection, sunglasses should have the following:
- Packaging or signage for the product indicating the ability to absorb and block 99 to 100 percent of both UVA and UVB light. Ideally, they should also guard against HEV light.
- Sufficient size to shield the eyes, eyelids, and surrounding areas. The more skin you cover, the better. Wraparound styles with a comfortable, close fit and UV-protective side shields are ideal.
- Durability and impact resistance.
- Polarized lenses to eliminate glare, especially when driving. They also increase comfort when you are out in the snow or on the water, where reflection greatly magnifies glare. Continuing glare can lead to fatigue, headaches, and even migraines.
Also look to see if the glasses meet ANSI and/or ISO standards for traffic signal recognition, which means that the lenses permit good color recognition, especially for tasks such as discriminating red from green traffic signals.
Sunglass lenses come in many shades; look for the lens color that provides you with the most comfortable vision.
Most importantly, when you purchase sunglasses, check the tags, labels, or packaging to make sure the lenses have proper UV protection. For an extra guarantee of safety, look for The Skin Cancer Foundation's Seal of Recommendation.
Today, UV absorption can be incorporated into most optical materials without hindering vision and at little extra cost. Ideally, all eyewear, including prescription glasses, contact lenses, and even intraocular lens implants should filter out UVA and UVB.
While sunglasses are essential for year-round sun protection, other safety measures are also important to protect against eye damage, skin cancers, and premature aging of the skin.
Hats are an especially important strategy. Wearing a hat with at least a 3-inch brim all around can block as much as half of all UVB rays from your eyes and eyelids. Hats or tinted visors also help block UV from entering your eyes from above.
Since sunglasses and hats cannot cover your entire face, sunscreen is also important.
Finally, whenever you are outside, seek the shade, especially between 10 AM and 4 PM, when sunlight is the most intense.
Remember, practice all these strategies year-round. And don't forget them when you are on vacation, summer through winter. Keep in mind that both water and snow reflect back 80 percent or more of the sun's rays, so that they hit your eyes and skin a second time. Also, remember that UV intensity increases with altitude, so be sure to protect yourself during activities such as skiing and hiking.