Sunglasses

Certain rays from the sun (called ultraviolet light) can damage your eyes. Wearing the right kind of sunglasses outdoors reduces your risk of eye damage from ultraviolet light.

Ultraviolet (UV) light from the sun may contribute to cataracts, which is the gradual clouding of the eye's lens. This clouding can cause loss of vision. Your vision can then be restored only by surgery.

There is some evidence that UV light may also contribute to development of age-related macular degeneration.

People who spend a lot of time outdoors in sunny climates tend to develop a type of degeneration of the outer coat of the eye called pterygium and pingueculum. It is thought that wearing sunglasses may reduce the risk of developing these.

Exposure to sunlight does contribute to the risk of skin cancer, and the eyelids are a common place for skin cancers.

Intense sunlight can cause sunburn of the cornea (the clear dome on the front of the eye). This may also be called snow blindness.

Most modern sunglasses provide good protection against ultraviolet rays. The more ultraviolet rays that are blocked, the more your eyes are protected.

If you are outdoors a lot, you may want to wear wrap-around glasses, which protect your eyes from the sides.

Polarized lenses reduce glare from other surfaces, such as water or snow. However, they don't block UV light unless they are combined with a UV-blocking coating. Mirror coatings alone do not provide UV protection and should be combined with a UV-blocking coating.

Photochromic lenses change their degree of darkness in response to lighting conditions. They are almost clear in low light and become darkly tinted in bright light. If you are considering photochromic lenses, ask your eye care provider if they block UV light.

Experts recommend that anyone who is going to be out in the sun long enough to burn or tan should wear UV-blocking sunglasses. Recently, researchers have found that the global ozone layer is thinner than it used to be, and more UV rays are reaching the earth. Some experts believe that wide-brimmed hats can keep about 50% of UV rays from reaching the eyes, but most agree that people should wear sunglasses also.

People who need to be sure they wear UV-coated sunglasses outdoors are people who:

• already have eye problems
• take certain medicines, such as tetracycline, allopurinol, phenothiazine, and psoralen
• work outdoors, such as farmers and some construction workers
• are outdoors at high elevations or near the equator
• spend a lot of time on snow or water.