What Sunglasses Really Do for Your Eyes

Sunglasses are a fashion accessory with a long history few of us ever stop to think about. While the look of these accessories often steals the show, shades pull double duty, offering protection and style.

About 800 years ago...

The origin of sunglasses can be traced all the way back to 1200–1600 A.D., when early tribes in the Arctic made "snow goggles" to block the glare of the sun and ice while hunting. In the 1200s, judges in China wore sunglasses to hide their facial expressions when interrogating civilians. In 1752, James Ayscough used his knowledge of microscopes to develop lenses to fix visual impairments related to color blindness and depth perception. Mass production of sunglasses by Sam Foster began in 1929.

The first polarized sunglasses, created by Edwin H. Land, sold millions of pairs. The famous Ray-Ban Aviator sunglasses were originally designed for the U.S. military, but eventually found success as a mainstream fashion accessory. Marilyn Monroe and Audrey Hepburn helped make cat-eye sunglasses popular during the 1950s, and since, sunglasses have changed shapes and styles, and grown ever more popular.

It's all about protection

The most obvious protection sunglasses provide is a physical barrier against external debris, which is especially valuable during allergy season, when pollen and other irritants are in the environment.

Sunglasses also function as a barrier between the eyes and sunlight, protecting the eyes from harmful ultraviolet (UV) rays. Without this barrier, you face an increased chance of eye diseases such as photokeratitis, pterygium, pinguecula, macular degeneration and cataracts. Photokeratitis is sunburn on the eyes, which can be painful and causes blurred vision and light sensitivity. Children are more susceptible to sun damage because their eyes are more sensitive to UV rays, which puts their retinas at higher risk.

The use of sunglasses also protects the eyelids and skin around the eyes from skin cancers, such as basal cell carcinoma.

What does sun damage look like?

A good rule of thumb is that if your eyes hurt or feel uncomfortable, you may be experiencing sun damage. Symptoms include discomfort or redness in the eyes, tears, blurry vision, swelling, light sensitivity, eyelid twitching, gritty feeling in the eyes, short-term vision loss and seeing halos. These symptoms usually last for six to 24 hours, but can sometimes last as long as a couple of days.

A good rule of thumb is that if your eyes hurt or feel uncomfortable, you may be experiencing sun damage.

The damage done to your eyes by sun exposure can be permanent or semi-permanent. If you consistently work outdoors and suspect your eyes have sun damage, it is recommended you wear sunglasses and a hat that provides shade until the symptoms subside. Depending on the severity of the symptoms, it may be best to see your doctor, who can refer you to a specialist.

Of course, the best way to deal with sun damage is to avoid sun exposure altogether. The next step is to monitor the UV index in your area, so you can prepare properly for each day. If you plan on hitting the beach, note that white sand reflects the sun's rays and can as much as double UV exposure—this is also true of snow in the wintertime.

The following steps are recommended:

• Wear only sunglasses for UV radiation levels of 2 or lower.
• Wear sunglasses, cover up and use sunscreen with UV radiation levels of 3 to 5. Sunscreen should always be reapplied every two hours.
• Wear sunglasses and a hat, cover up and use sunscreen for UV radiation levels of 6 to 10.
• When the UV radiation level is more than 11 and you can't avoid exposure, use all the sun protectant gear you have.

Fun in the sun is a staple year-round, so be sure to stay safe and protect your eyes while creating outdoor memories.