Snowblind — it's a frightening word. Thankfully, it's a condition that is totally preventable.
What is Snowblindness?
Snow blindness is a painful, temporary loss of vision due to overexposure to the sun's UV rays. The medical term for snow blindness is photokeratitis ("photo" = light; "keratitis" = inflammation of the cornea).
Essentially, snow blindness is caused by a sunburned eye - or more specifically, a sunburned cornea. And like sunburned skin, by the time you notice symptoms of snow blindness, you've already been in the sun too long.
You Don't Need Snow To Become Snowblind
Though photokeratitis is commonly called snow blindness, the condition can (and often does) occur in the absence of snow.
The terms "snowblind" and "snow blindness" have become popular because snow is highly reflective of ultraviolet radiation. In fact, snow can reflect more than 80 percent of the UV rays that fall upon it. Also, skiing, mountain climbing and snowboarding usually take place at relatively high altitudes, where the sun's UV rays are stronger. Combined, these factors can double your risk of getting sunburned eyes, compared with being outdoors at lower altitudes in the summertime.
To prevent snow blindness on the slopes, wear sunglasses with a close-fitting, wrap-style frame or snow goggles. Make sure the lenses block 100 percent of UV rays.
But water and white sand also are highly reflective of the sun's UV rays and increase the risk of snow blindness.
Television journalist Anderson Cooper experienced snow-free snow blindness first-hand a few years ago when he spent a couple hours on a boat in Portugal without sunglasses and ended up "blind for 36 hours," according to his report of the incident.
After the day in the sun, he woke up in the middle of the night with symptoms of burning eyes and a feeling there was sand or grit in his eyes. "It turns out I...sunburned my eyeballs," he said on his television show, Anderson Live. "I had no idea you could do this."
Not only can you become snowblind without snow — it can happen without sunlight, too! Photokeratitis sometimes occurs from man-made sources of ultraviolet radiation, such as a welder's torch. Though this type of injury usually is called a "welder's flash" or "flash burn" of the cornea, the mechanism of action and symptoms are very much the same as those of snow blindness.
Sun lamps and tanning booths also can cause photokeratitis and temporary "snow" blindness if proper eye protection is not used.
