Most people are surprised to learn that their eyes are equally as susceptible to sun damage as their skin. The cornea, a clear layer that covers the pupil and iris, is composed of epithelial cells similar to those that make up the skin. Both our corneas and our skin function as protective barriers for the deeper, more fragile components of our bodies. Although these layers are intended to take a beating from the environment, overexposure to the sun can be painful and have a lasting impact on one’s health.

For most people, small doses of ultraviolet (UV) light don’t result in significant injury. However, prolonged or magnified exposure to UV radiation can cause severe inflammation to the cornea and conjunctiva (the layer that lines the insides of the eyelids and covers the whites of the eyes). This painful eye condition is known by several different names, including snow blindness, arc eye, flash burns, ultraviolet keratitis and photokeratitis.

Natural sources of UV radiation can be harmful, especially in highly reflective environments, such as ice or snow fields, out on open water, or in areas covered with white sand. Tanning beds, arc welders and certain kinds of lamps produce artificial UV radiation can be just as dangerous. Furthermore, repeated ultraviolet damage to the cornea can lead to more serious ocular disorders, some of which may be sight-threatening.

Unfortunately, individuals usually do not realize that they have sunburned their eyes until six to 12 hours after exposure. For example, CNN news anchor Anderson Cooper experienced photokeratitis in 2012 after spending a few hours out on a boat without wearing sunglasses. The sunlight reflecting off the water caused such severe damage that Cooper was temporarily blinded for about 36 hours.

Symptoms of photokeratitis include swelling, redness, pain, and general sensitivity and irritation of the eyes. Typically, damaged corneas will repair themselves in 24 to 48 hours, but if the burn is particularly severe, it’s important to see a doctor. They may use an eye drop solution containing fluorescein dye during their exam to better assess the extent of the UV damage.

Inflamed corneas can be susceptible to infection, so preventative antibiotic eye drops are often prescribed for more serious burns. In addition to plenty of rest and avoiding further exposure to the sun or bright lights, artificial tears, cold compresses and over-the-counter pain relievers can be used to minimize symptoms.

According to Dr. Dave Ardaya, O.D. with the California Optometric Association, “While we should all take care to protect ourselves from UV radiation, there are some people who are more at risk. Individuals with light eyes (blue, green and hazel) may be at higher risk of developing eye diseases tied to UV radiation.” Additionally, Dr. Ardaya points out that some medications can cause increased sensitivity to the sun. Commonly prescribed drugs that cause photosensitivity include antibiotics like ciprofloxacin and co-trimoxazole, certain diuretics, non-steroidal anti-inflammatory drugs (NSAIDs), and antiarrhythmic medications used to treat irregular heart rhythms. UV exposure while taking these drugs may result in phototoxic reactions of the eyes and skin.

Simple precautionary measures can significantly reduce the risk of corneal damage. Suitable eye protection is of utmost importance to prevent photokeratitis and many other eye conditions. “Scientific studies and research have shown that even exposure to small amounts of UV radiation over a period of many years increases the chances of developing cataracts and macular degeneration,” warns Dr. Ardaya.

Whether you are at the beach, out on the water fishing, welding something in your garage or skiing, be sure to wear appropriate eyewear, such as sunglasses, a welding helmet or ski goggles. Dr. Ardaya specifically recommends wraparound sunglass designs. The larger frames offer increased protection for both the eyes and eyelids, which can be prone to various skin cancers like basal cell carcinomas.

“Sunglasses should block out 99 to 100 percent of UVA and UVB radiation and screen out 75 to 90 percent of visible light,” Dr. Ardaya recommends. “Polarized lenses are a good option because they can specifically block the most prominent light rays while maintaining clear vision.”

There is no excuse for forgoing proper eye protection, especially since many affordable UV-blocking sunglasses are widely available. The next time you and your loved ones head outside, don’t forget to bring your shades.