The Importance of Wearing Sunglasses

I filled my first prescription for sunglasses over a decade ago at the strong urgings of a trusted doctor. After balking at shelling out $500.00 dollars or more for what I then considered a frivolous extravagance, I was informed that these glasses would prevent cataracts and surgery in later life.

My doctor's warnings are seconded by the Environmental Protection Agencies (EPA) findings in their publication: "A Guide to the UV Index." which includes cataracts along with sun burns and skin cancers in the list of ultraviolet's hazards. The UV Index was completely revamped in 2004 to incorporate the latest recommendations from the World Health Organization and other leading experts.

According to the EPA, exposure to the sun at levels as little as 1-2 on the scale, equivalent to levels seen in New York City during winter months, calls for the eye protection provided by a good pair of sunglasses. During Summer, some American cities such as Phoenix, Miami and Honolulu may experience exposure levels as high as 10 to 12 on this same scale. So eye protection is recommended regardless of the season or city. In fact, winter snow can actually double normal exposures due to reflection. Surprisingly, overcast cloud cover provides no relief from UV rays.

In addition to cataracts, excessive sun exposure is implicated in macular degeneration, corneal burns, and the formation of a flesh membrane in the eye known as pterygium. According to EPA figures, more than half of all Americans age 65 or older have some evidence of cataracts, while 13 million Americans as young as 40 years of age have already been diagnosed with this disease.

And UV exposure has been growing since the 1970s according to the EPA

According to Dr. Gary Heiting, OD, ultraviolet radiation is not the only eye danger. High Energy Visible Light (HEV) also known as blue light can also cause significant damage including increased risk for macular degeneration and retinal damage. Although lower in energy than UV, light in this frequency (400-500 nm) has the ability to penetrate deeply into the eye. Low levels of vitamin C and antioxidants in the blood can exacerbate the damage.

Dr. Heiting recommends wrap-around or larger styles for increased sun protection. It is best to consult an optician for lenses offering 100% ultraviolet protection. Your existing pairs of glasses can also be measured to determine what level of UV protection they provide.

Although no one shade or color is associated with superior protection from UV, bronze, copper or reddish-brown lenses are most effective at blocking High Energy Visible Light. The doctor recommends pairing sunglasses with a wide brimmed hat to reduce exposure up to 50%.

Sun damage is cumulative. Children may need sun protection even more than adults, especially since they spend more time outside.

Contact lens wearers are also advised to wear sunglasses. Although contact lenses incorporate UV protection, they cover a limited area. Wearing sunglasses will protect the conjunctiva and other tender areas.

Dark eyes are no protection either. Although darker skin protects somewhat against sun, darker eyes provide no protection whatsoever according to Dr. Heiting.

Athletes may have additional requirements. According to Errin Morgan, selection of the correct style of sunglass may lead to enhanced performance. Polycarbonate lenses are suitable for athletes who need shatter-resistance.

Although all colors and shades can potentially protect against UV rays, certain tints may be more suitable for sport use. For example, skiers may benefit from a high contrast amber lens, while others may prefer the more accurate color reproduction of a gray tint. Colors are available to help a golfer see the lie of the grass, while a different shade will increase the contrast of a bird against the sky for more efficient hunting. Specialized tints are available for increased performance in a variety of sports.

Polarized lenses are favorites of water sports enthusiasts and skiers because they reduce surface reflection, but some experts prefer to avoid using such lens in downhill and mogul skiing since they can also render patches of ice less visible.

Wavefront-guided lenses are a new technology that offers significantly increased visual acuity in low light but also improve vision somewhat during the day. This technology allows for a 100% custom prescription that corrects minor imperfections in vision that regular eyeglasses cannot.

Sunglasses are more than an ornament, they are an increasingly important weapon in the fight for your vision.

Sources:
www.epa.gov/sunwise/doc/uviguide.pdf
www.allaboutvision.com/sunglasses/spf.htm
www.allaboutvision.com/sunglasses/performance.htm