It is possible for damage to occur in an afternoon outing or to build slowly over a period of years. Everyone should wear UV-absorbing sunglasses year round when in the sun. Good sunglasses provide safe and comfortable vision. Protect the long-term health of your eyes by choosing sunglasses that offer maximum protection from the sun. Special purpose is for very bright light, such as skiing, tropical beaches, and mountain climbing.
Cosmetic is for lightly tinted lenses to use shopping and other around-town uses.
Good sunglass lenses block 75 to 90 percent of visible light. Take caution to protect against blue light exposure. Lenses tinted yellow, brown, or amber absorb blue light and enhance contrasts in haze or fog. Large sunglasses are better than small ones because they protect against light coming in from the sides, top, and bottom of the frames. Glasses that slip even a quarter inch from the forehead allow about 20 percent more UV rays into the eyes.