Fashion aside, sunglasses serve a true function - protecting eyes from the harmful rays produced by the sun. You're probably well aware of the needed to protect your skin from the sun, but it's equally important to protect our eyes.
Ultraviolet (UV) radiation consists of invisible rays from the sun. The three bands of UV light are UVA, UVB and UVC. UVC rays are of little concern as they are absorbed by the upper atmosphere and do not reach the earth's surface.
UVB ray s are the ones that burn the skin and can damage the eyes. Combined with cold wind and snow, UVB has the potential to cause snow blindness (photokeratitis), a temporary (lasting 12 to 48 hours).
Although not all experts and scientists agree, there is some research that suggests that daily exposure to UVB in very bright sunlight over a period of many years may cause cataracts, a gradual clouding of the lens of the eye.
What to look for when you're buying sunglasses; Sunglass standards for lenses place limits solely on UVB and UVA ray, but bear in mind that both the standards and labeling are voluntary, not mandatory. According to these standards, sunglasses must block at least 70% of UVB and at least 60% of UVA.
To best protect your eyes look for sunglasses that provide at least 98% protection from both UVA and UVB rays. Some of the higher priced products with polycarbonate, or plastic lenses can claim to block 100% of the UV rays.
Tuesday, June 5, 2007
Subscribe to:
Posts (Atom)