For most people, sunglasses are a cool fashion accessory. Their main concerns are appearance, comfort and price. But many consumers overlook what eye doctors consider the most important factor: protection from ultraviolet radiation.
"While most people understand the link between the sun's damaging rays and skin cancer, many are not aware of the connection between ultraviolet radiation and eye damage," says Marc Werner, MD, a New York City ophthalmologist .
You know that little label on most sunglasses that refers to UV protection? Werner says you should buy sunglasses stating they block 99 to 100 percent of ultraviolet light. Some labels say "UV400 protection," which refers to wavelength and blocks all harmful rays.
"The depletion of the ozone layer has allowed higher levels of UV radiation to reach us, so it's more important than ever to protect our skin... and our eyes," he says. "We put sunblock on our body, but we forget the eyelids, and they are prone to skin cancer, too. Sunblock around the eyes can cause irritation, but sunglasses with an adequate UV block safeguard our eyes and eyelids the way sunscreen can protect our skin."
Mounting evidence suggests that prolonged exposure to UV radiation over the years can contribute to the development of eye diseases, such as cataracts and macular degeneration. The effects of UV radiation on the eyes are cumulative. Damage today leads to vision problems later, which is why authorities recommend that we should protect our eyes starting at an early age.
Sun exposure has also been linked to an abnormal growth on the corner of the eye near the nose called a pterygium. Although non-cancerous, it can partially block vision and sometimes requires surgery to be removed. Excessive exposure to UV light can also cause more immediate damage, such as a corneal burn. Just one day at the beach without proper eye protection can cause a temporary, but painful burn to the surface of the eye, similar to a sunburn on the skin. This can lead to temporary vision loss.
People should be mindful of reflected sunlight, which can be particularly dangerous as UV light radiates directly from the sun, but it is also reflected from the ground, water, sand, snow and other bright surfaces.
In addition to reducing light and glare, sunglasses that block harmful UV-A and UV-B rays are a necessity and should be worn anytime someone is outdoors, even in the winter and even if it isn't very sunny, according to Werner.
Generally, it isn't necessary to buy expensive shades to get the protection one needs, he says. Less costly brands with labels that indicate 99 - 100 percent UV-A and UV-B protection generally offer as much protection as designer labels. Anyone who wants to make sure their sunglasses have adequate protection can have them tested by a machine called a photometer in an ophthalmologist's or optician's office. As for the lens color, it doesn't affect how well they protect your eyes from UV light. Even light-colored lenses can do the trick, but gray and brown lenses distort colors the least.
To best protect your eyes please read the following:
* READ THE LABELS. Look for sunglasses whose labels state 99% to 100% protection from UVA and UVB light. Some labels say "UV400 protection," which refers to wavelength and blocks all harmful rays.
* CHOOSE lenses that are large enough to shield the eyes from most angles.
* WEAR wrap-around sunglasses and a wide-brimmed hat or cap if you'll be out in the sun for a prolonged period or work outdoors.
* CONSIDER purchasing daily eyewear, such as prescription eyeglasses or contact lenses, with UV-blocking lens materials. But even if you're wearing contact lenses with UV protection, you still need to wear sunglasses, because the contact lens does not protect the entire eye.
* MAKE SURE CHILDREN always wear sunglasses. They are at special risk from the harmful effects of UV rays. May sure the sunglasses fit well and are not damaged. Have your child wear a wide-brimmed along with the sunglasses for extra protection.
Babies should ALWAYS wear a hat to shield their eyes and faces from the sun.
* NEVER stare directly at the sun. It can permanently scar the retina, the area at the back of the eye.
Most "age-related macular degeneration" - the loss of visual acuity in the macula, the center of the retina, where the optic nerve comes in and most vision is focused - is actually the result of UV mileage...and certain dietary contributors (refined carbohydrates apparently play a role too).
The reasons are simple: High photon energy is the same stuff that degrades auto dashboards and nylon. These highly energetic light particles strike atoms, knocking electrons out of their normal orbital shells, and degrading the materials. Oxygen atoms (atomic # 8)are particularly vulnerable to such electron shifts, and the retina is one of the most oxygenated tissues in the human body. Some people think you can adapt your eyes to going without shades - not so. Snow-blindness (which is very painful) is an acute form of this damage. Snow, concrete, and water can reflect virtually 100% of solar UV, and that's why people, and their eyes, get so fried on sunny days around these surfaces.
Virtually all plastic, polycarbonate, or tinted glass lenses will remove most harmful rays, although light-tinted shades may still let in excessive visible light, making you squint. Infrared light (heat) doesn't harm eyes long term, but causes a temporary 24-hour decrease in night vision ability. So driving back at night from a hot, sunny day at the beach can put you at greater risk from auto accidents.
Shangri-La 2: "I dunno . . . he's always wearing shades."
I think this means that the "UV400 protection" label also means you're safe. But I'm not sure.