Regardless of style, sun glasses should protect your vision. Recent scientific advancements have greatly expanded understanding of the eye, creating materials to defend them.
The bright light of a cloudless day can be painful and distracting, so most people wear sunglasses when outside, especially while driving. At the other end of the spectrum, fog and smoke decrease visibility. The amber-colored lenses of recent decades filter out the additional blue light scattered by low-lying clouds, giving drivers a more balanced, clearer view of the road. Polarized sunglasses help cut down the glare of reflected light.
Ultra-violet radiation (known as UVA and UVB) has been shown to be a contributing factor for cataracts and many other eye problems. Look for UV-rated sunglasses, which block at least 70-percent of UVA and 60-percent of UVB light. Some sun glasses claim to block 100-percent of both.
The other main danger is impact damage. Flying debris ranges from annoying (specks of dust) to sight-threatening (pebbles kicked up by passing cars). The American National Standards Institute (ANSI) is a private organization dedicated to producing quality goods in the USA. For sunglasses, ANSI requirements include dropping a 1-inch steel ball on the lens from four feet high and shooting a quarter-inch ball at 150 feet per second. If no part of the lens touches the eye when impacted, the glasses pass the test and may advertise themselves as ANSI compliant. This is especially useful in sport eyewear.
Sunglasses are one item where the highest price doesn't always mean the best product. Some designer glasses may not include the safety features that your eyes deserve. Of course, at Overstock.com, discount sunglasses and designer sunglasses can be synonymous.
By the way, when buying sunglasses online, you may find that so-called discount sunglasses, allegedly from top designers, are, in fact, cheap knock-offs instead of the real deal. If so, the chances of a refund are pretty slim, so buy from a reputable dealer like Overstsock.com, one with a long history of selling authentic, quality products.