How long sunglasses last

There is no current recommendation for when, exactly, people should retire their old pairs—and protecting eyes from the sun is important anywhere in the world, as UV exposure can lead to cataracts , retina damage, and other long-term eye problems and vision loss. To be certified in one of these categories, lenses must pass a test in which they are exposed to a watt sun simulator lamp for 50 hours at a distance of 30 centimeters.

This is equal to two full days of average summer sun exposure, or four days of average winter sun exposure, the study authors write. So in actuality, this test is only equivalent to A previous survey found that Brazilians wear their sunglasses for an average of two hours a day for two years straight.

The aging tests, the authors argue, should also be revised to reflect this. In order to represent average consumer use throughout the country, they calculate that both the time and distance of exposure in the sun-simulator test needs to change to Most sunglasses today have UV protection embedded in the lens rather than coated over it, and most reputable brands list UV protection on their label. Most opticians will test them for free, and it takes less than 30 seconds.

Sunglasses are to the eyes what sunscreen is to the skin. So while they may filter out ambient light and glare, that additional exposure to UV rays increases your risk for cataracts, macular degeneration, and even development of ocular melanoma—a rare cancer.

Polarization has nothing to do with UV light absorption, but many polarized lenses are now combined with a UV-blocking substance. We love a pretty pair of sunglasses, but as always we want fashion AND function. Bonus, that new pair will go perfectly with our stylish sun protection! November 10, Read More. November 03,