Over a dozen studies have shown that spending extensive time in sunlight without proper eye protection can increase the chances of developing age-related eye diseases, such as cataracts and macular degeneration. In light of these findings, ophthalmologists now recommend their patients to wear UV-absorbent sunglasses and brimmed hats when in the sun for periods of time long enough to develop a suntan or sunburn.
When shopping for UV-absorbent sunglasses, be very careful to investigate the product. Many people make the mistake of assuming that darker colored lenses provide better UV-absorbing capabilities. In truth, however, the degree of UV protection in a pair of sunglasses stems from the presence of a chemical coating applied to the surface of the lens. Look for sunglasses that absorb 99 or 100% of all ultraviolet (UV) light. Many manufacturers term the UV absorption rating in terms of wavelength. In these cases, look for sunglasses with labels that say “UV absorption up to 400 nm.”
Another factor to consider when shopping for sunglasses that provide effective UV protection is the shape of the frame and lenses. Wrap-around sunglasses that cover the sides of the eyes help to prevent light from shining around the frames and into the eyes. Studies have shown that significant UV rays enter around smaller sunglass frames, reducing the benefits of wearing protective lenses. Wearing sunglasses with larger frames and a close, wrap-around fit to the face help to protect the eyes from all angles. Such sunglasses are especially important for commercial fishermen, mountain climbers, skiers, and anyone who spends time at high altitudes or on bodies of water.
A final consideration to make when buying sunglasses is the polarization qualities of the lenses. Polarized lenses eliminate reflected glare in the wearer’s view, such as sunlight bouncing off of water, pavement, or snow. This quality is especially important when doing such activities as fishing, driving, and skiing. It is important to note, however, that polarization has nothing to do with UV light absorption. It is merely a mechanism to orient the sunlight that passes through lenses so that the view through the sunglasses is clearer and free of glare.