Potential Effects of UV Radiation on Eyes
Long-term exposure to UV radiation can lead to cataracts, skin cancer around the eyelids, and other eye disorders. And new research suggests the sun’s high-energy visible (HEV) radiation — also called “blue light” — may increase your long-term risk of macular degeneration. People with low blood plasma levels of vitamin C and other antioxidants especially appear at risk of retinal damage from HEV radiation.
In the short term, excessive exposure to UV radiation from daily activities, including reflections off of snow, pavement, and other surfaces, can burn the front surface of the eye, similar to a sunburn on the skin.
The cumulative effects of spending long hours in the sun without adequate eye protection can increase the likelihood of developing the following eye disorders:
- Cataract: A clouding of the eye’s lens that can blur vision.
- Snow Blindness (Photokeratitis): A temporary but painful burn to the cornea caused by a day at the beach without sunglasses; reflections off of snow, water, or concrete; or exposure to artificial light sources such as tanning beds.
- Pterygium: An abnormal, but usually non-cancerous, growth in the corner of the eye. It can grow over the cornea, partially blocking vision, and may require surgery to be removed.
- Skin Cancer around the Eyelids: Basal cell carcinoma is the most common type of skin cancer to affect the eyelids. In most cases, lesions occur on the lower lid, but they can occur anywhere on the eyelids, in the corners of the eye, under the eyebrows, and on adjacent areas of the face.
Outdoor Risk Factors:
- Geographic location. UV levels are greater in tropical areas near the earth’s equator. The farther you are from the equator, the smaller your risk.
- Altitude. UV levels are greater at higher altitudes.
- Time of day. UV and HEV levels are greater when the sun is high in the sky, typically from 10 a.m. to 2 p.m.
- Setting. UV and HEV levels are greater in wide open spaces, especially when highly reflective surfaces are present, like snow and sand. In fact, UV exposure can nearly double when UV rays are reflected from the snow. UV exposure is less likely in urban settings, where tall buildings shade the streets.
- Medications. Certain medications, such as tetracycline, sulfa drugs, birth control pills, diuretics and tranquilizers, can increase your body’s sensitivity to UV and HEV radiation.
Surprisingly, cloud cover doesn’t affect UV levels significantly. Your risk of UV exposure can be quite high even on hazy or overcast days. This is because UV is invisible radiation, not visible light, and can penetrate clouds.