Many people wear sunglasses to be fashionable but when buying sunglasses, one should also consider protection from the sun. UV radiation in sunlight causes sunburns to the skin and eye damage. There are three types of UV radiation: UVA, UVB, and UVC. UVC is of little concern since it is absorbed by the upper atmosphere.
UVB causes sunburns to the skin and snow blindness, a temporary but painful damage to the cornea. There is some controversial evidence that UVB causes cataracts. Many eye doctors feel that exposure to UVB causes damage to the eye such as cataracts and retinal disease like macular degeneration. Therefore it is important to consider protection from UVB when buying sunglasses.
UVA is absorbed by the human lens. It is not proven at this time whether UVA damages the lens of the eye. Many eye doctors feel that UVA does damage the eye. If you have had cataract surgery the lens of your eye does not absorb UVA unless your implant is an UV absorbing implant. Therefore it is also important to consider protection from UVB when buying sunglasses.
The sunglass labeling and standards are voluntary not mandatory. When purchasing sunglasses, one should select lenses that provide at least 60% protection from UVA and 70% protection from UVB. In order to get the maximum protection, one should purchase lenses that offer 98% protection. There are lenses available in polycarbonate, plastic and glass, which block 100% of UVA and UVB.
With 300 days of annual sunshine here in Colorado, there is a great need for protection against harmful ultraviolet radiation. It is also important to remember that 80% of your sunlight exposure occurs when we are children. Therefore consider good sunglasses for your children.
Randy Hertneky, O. D.
Yuma Vision Source
105 S. Main St
Yuma, CO 80759
Wray Vision Clinic
415 Main Street, Wray, Colorado 80758
Author: Dr. Randy Hertneky
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