People have been wearing eyewear to block the sun for roughly 2,000 years. In their article about the increasing trend of wearing stylish sunglasses, Life magazine approximated that about 30% of sunglasses bought were worn for eye protection, and the remaining 70% were used to accessorize. This figure is still accurate today since 75% of adults in the United States wear either prescription sunglasses or Plano sunglasses (eyeglass lenses with no curvature for vision correction). In order to effectively protect your eyes from damaging UV rays, lenses must meet certain standards. Lightly tinted cosmetic lenses are required to block 70% of UVB rays. Medium-to-dark tinted general purpose sunglass lenses have to block 95% of UVB rays and the majority of UVA rays. Special-purpose lenses used in very bright sunlight are required to block 99% of UVB rays. Transition lenses, also called photochromic lenses, are sunglass lenses that darken in the sun and lighten when you're in the shade or indoors. Here are some facts to think about when deciding whether photochromic lenses are a good choice for you.
Any eyeglass wearer knows that it's a hassle to keep switching between your regular glasses and your stylish sunglasses when you go indoors or outdoors. Transition lenses eliminate the constant juggling of eyewear. Someone in America will lose, break, or sit on a pair of glasses once every 14 minutes. Children and adults alike won't be as apt to lose their glasses if they only have one pair to take care of. Transition lenses can be a money-saving choice because this might be the only pair of glasses you'll need.