You probably know about the damage the sun's ultraviolet (UV) radiation can do to your skin. But do you know about the damage UV radiation does to the eye?
This UV exposure adds up over time: The exposure while on the beach as a child combines with sun exposure as you age, resulting in damage later in life.
The rays that pass through the pupil of the eye are absorbed by the lens of the eye. This UV radiation may cause cataracts in the lens of the eye.
Solar radiation that reaches the surface of the eye is focused and concentrated by the cornea, the clear outermost layer of the eye. Studies show that this UV radiation, which can reach the eyes from above, below and the sides, may cause changes to the tissue on the opposite side of the eye. Small tissue elevations, called pingueculea and pterygia, may result.
The American Optometric Association (AOA) recommends the use of sunglasses that block 99-100 percent of UV-A and UV-B rays to protect the eyes from this radiation. However, many sunglasses styles do not protect the eyes from the solar radiation entering from the sides or around sunglasses.
Some contact lenses offer additional protection. These contact lenses absorb UV radiation by reducing the amount of radiation that reaches the surface of eye. The contact lenses also protect the eye from the radiation that comes from above or around the sides of sunglasses.
The U.S. Food and Drug Administration (FDA) has standards for UV-blocking contact lenses based on American National Standards Institute Z80.20 standards. There are two classifications of UV-blocking lenses:
- FDA Class I blocker. recommended for high exposure environments such as mountains or beaches. The lenses in this classification must block more than:
- 90% of UVA (316-380 nm wavelengths) and
- 99% of UVB (280 – 315 nm)
- FDA Class II blocker. recommended for general purposes. These lenses must block more than:
- 70% of UVA and
- 95% of UVB
People who wear contact lenses and do not wear wrap-style sunglasses can further protect themselves from UV radiation by wearing contact lenses that block UV.
Talk to your optometrist about your outdoor activities in all seasons so he or she can help identify your risk of UV exposure and the appropriate protection.