During a stroll down the sunglasses aisle, you may notice that some pairs advertise UV protection. UVB stands for ultraviolet B, which are shortwave rays from the sun. Ultraviolet A, or UVA, rays tend to gain the most attention in terms of protection because they have longer waves to penetrate body cells. However, UVB rays can do just as much damage in terms of sunburnt eyes, macular degeneration and cancer. Choose sunglasses that include both kinds of protection for optimal eye health.
Immediate Effects of UVB
UVB rays are the shorter rays emitted by the sun. Without sunglasses, sunlight can burn the eyes, which can cause temporary blindness. Repeat offenses can result in long-term vision problems, so it is important to wear full UV-protection glasses every day. On cloudy days, UVB rays are intensified—this is why wearing sunglasses is beneficial in all types of weather.
Long-Term Eye Damage
UVA rays can penetrate the lens of the eye, which is located behind the iris. UVB rays cannot penetrate this deep layer; however, these short waves can still affect the cornea, the outer layer of your eye. Without proper protection, UVB can break down the cornea over time. This exposes the retina, or back portion of the eye wall, leaving it vulnerable to permanent damage, as well as blindness. A disrupted cornea can also make color differentiation difficult by distorting the ability to recognize light.
Identifying UVB Glasses
When shopping for sunglasses, look for manufacturer stickers on the lenses or on accompanying tags that state that the product offers 100-percent protection against both UVA and UVB rays. The type of plastic used can also make a difference in terms of protection. According to All About Vision, polycarbonate lenses offer 100-percent UV protection. Those made of triacetate absorb 40 percent of rays and CR-39R plastic absorb 88 percent. Sunglasses are offered in all styles, colors and price tags, so don’t assume a more expensive pair offers full UV protection.
Glasses with full UV-ray protection are essential every day—even if it’s overcast. If you forget your sunglasses at home, protect your eyes in other ways. Wear a hat to be stylish and to guard your eyes from the sun. The American Academy of Ophthalmology recommends a brim of at least three inches for optimal eye protection. Another way to protect your eyes is to avoid looking into direct sunlight or at reflective grounds, such as sand, gravel and water. If you spend a lot of time around the water, look for polarized sunglasses, which reduce reflective glare.
References and ResourcesMedline Plus: Sun Protection
American Academy of Ophthalmology: Overexposure to Sun's Rays Can Cause Painful, Temporary Blindness
World Health Organization: The Known Health Effects of UV
All About Vision: Q&A on Sunglasses and UV Light