Every day of the year, whether it is sunny or overcast, we are exposed to ultraviolet (UV) radiation from the sun. Most people know how harmful UV radiation is to their skin, but many people don't realize that UV radiation is also harmful to their eyes. If you expose your eyes to excessive amounts of UV, the short term effect is likely to be photokeratitis, which is a fancy word for sunburn of the eye. The symptoms can be painful and include redness, a gritty sensation, extreme sensitivity to light, and excessive tearing. Fortunately, these symptoms are usually temporary and rarely cause permanent damage. Unprotected exposure to UV radiation over long periods of time, however, increase the risk of developing more serious, and sometimes irreversible, issues such as cataracts, certain cancers of the eye, and macular degeneration.