Most people choose sunglasses for their style, shape or color of the lens. But they’re missing the bigger picture. Although sunglasses can make a person look cool, sophisticated or even glamorous, fashion is not the key issue to consider here.
Rather, it’s safety.
That’s where the American National Standards Institute, or ANSI, comes in. The purpose of ANSI is to protect the safety of consumers. That even extends to non-prescription eyewear. A committee working with the organization developed standards called ANSI Z80.3 to regulate the safety of sunglasses.
According to these standards, the ideal sunglasses should block at least 99 percent of ultraviolet, or UV, rays. Some labels may indicate “UV absorption up to 400 nm,” which, according to the American Cancer Society, is technical jargon for “100 percent UV protection.”
Two types of UV rays can damage the skin, including delicate skin surrounding the eyes. UVA rays are more associated with premature aging and wrinkles, but are thought to play a role in some skin cancers. UVB rays, on the other hand, can directly damage the DNA of skin cells and are blamed for most skin cancers.
While the sun and its connection to skin cancer are widely known, less well known is the sun’s impact on the eyes. UV rays can damage the cornea and lens of the eye and may play a role in the development of cataracts and macular degeneration. A cataract is a clouding of the lens of the eye, while macular degeneration destroys the sharp, central vision. Both conditions are leading causes of blindness, according to the National Eye Institute.
While UV protection is paramount for sunglasses, lens safety and quality are also key. The ANSI Z80.3 standard stipulates criteria for transmittance (ability to distinguish between colors), quality (prevention of cracks or bubbles) and durability, such as flame and impact resistance.
There is a misperception that the darker the lens the greater protection from the sun. Not so. UV protection comes from an invisible chemical applied to the lens. The tint of the lens is more about taste.
Additionally, polarized lens do not afford additional protection from the sun. Rather, these special lenses help deflect glare and are recommended when on the water or in snow.
Large-framed or wraparound sunglasses tend to provide more protection from light coming in from different angles. Some contact lenses are now made to block most UV rays. Because they don’t cover the whole eye and surrounding skin, however, they do not afford sufficient eye protection.
Damage to the eye is cumulative. That’s why children should wear sunglasses as well. Eye specialists recommend that children’s glasses should be just smaller versions of real, protective adult sunglasses. Toy sunglasses will not do.
Clouds do not block UV light. The rays can pass through haze and clouds, which is why ophthalmologists recommend wearing sunglasses all year round, and not just in summer.
The good news is that price is not a factor in buying safe shades. Designer sunglasses and ones bought in a drug store often work equally well.
Just look for the sticker or label that indicates one or more of the following:
Blocks at least 99 percent of UV rays
UV absorption up to 400 nm protection
ANSI Z80.3-2001 standard
If there is no label, don’t assume the sunglasses provide any UV protection.
For more eye safety information, go to the Bay State Banner.