There's more choosing shades than how good they look on you. Your sunglasses should keep damaging sunrays away from your eyes.
Do you love how cool your sunglasses make you look? If you really want to be comfortable in the glare and protect your eyes -- and your children's eyes -- from future cataracts, there is more to selecting sunglasses than mere "coolness" (desirable as that is).
Although the human body is aces at replacing some damaged cells, the cells in the lens of the eye are never replaced. Damage from ultraviolet and (to a lesser degree) infrared rays can build up over a lifetime and lead to cloudy areas on the lens of your eye called cataracts. It's hard to see through cataracts, and they often must be removed surgically. Macular degeneration, an eye condition resulting from damage to the retina, also may be accelerated by too much unfiltered sun blasting the retinas.
"The thing you want to guard against mainly is ultraviolet rays," explains Lee Duffner, MD, professor of ophthalmology at the
Besides UV, brightness is an issue. What people don't realize, Duffner says, is that going from inside to outside involves confronting light thousands of times brighter than that going into the eye the moment before. Brightness is a comfort issue -- it's uncomfortable to go into the sun from the shade and to have undimmed light flowing into your eyes.
So the darker the lens in your sunglasses the better? "Clear glass transmits 90% of light, Duffner says. As the glasses get darker, less and less light goes through. Lightly tinted lenses let in 75% to 80% of light, Duffner says. Military standards specify that only 15% of light should penetrate. "You can still see very well with 10% to 12% of light only," he notes. "I recommend glasses in the 20% range."from www.dasego.com
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