Mark Pattison, a former NFL player, successfully climbed Mount Everest in 2021 despite suffering from a case of snow blindness on summit day. He couldn’t see out of one of his eyes.  

“When we woke up that morning and started our climb at 12:30, it was awful, we had snow and sleet coming across, blowing hard. All of that resolved itself around 4:30 in the morning and we had a beautiful sunrise, my problem is that I ended up getting snow blindness.”  

He summited Mount Everest, capping his campaign to climb the Seven Summits as part of an epilepsy awareness campaign. Pattison documented his crusade in the Emmy Award-winning NFL 360 film “Searching for the Summit.” 

Pattison was lucky. Snow blindness, a painful eye condition caused by overexposure to the sun’s ultraviolet (UV) rays, can happen in a matter of minutes. 

Remember racer Doug Swingley, who removed his goggles during the 2004 Iditarod sled dog race for a quick look ahead? His vision became extremely blurry, according to the American Academy of Ophthalmology, and he had to leave the race to receive medical treatment. 

Fortunately, snow blindness is not usually permanent and it’s often short-lived. The symptoms are caused by temporary damage to the cells on the surface of the eye. If there is vision loss, it typically resolves in 24 to 72 hours. If it doesn’t, contact your doctor immediately. 

Snow blindness doesn’t occur only in the polar region. It can affect anyone enjoying snow sports —hiking, snowshoeing, skiing and snowmobiling — in the bright sun. 

A Sunburn of the Eye 

There’s a reason you squint in the sun. It’s your body’s way of naturally protecting itself. 

“The sun’s ultraviolet rays can burn the cornea of the eye, causing irritation, pain and blurred vision,” said Jeff Weinstein, a paramedic and a Medical Operations supervisor for Global Rescue. 

With the name — snow blindness — you would think those most at risk are the adventurer travelers outside in snowy terrain, across a snowfield or in a high-altitude winter environment without proper eye protection. And you’d be right; fresh snow reflects about 80% of UV radiation. 

Water and white sand are also reflective, so spending a day on the ocean or lake also puts you at risk. Your eyes are prone to sunburn from a direct hit from the sun combined with the reflection of the sun from the water or sand. 

Location and Season Make a Difference 

Of course, you’ll want to protect your eyes at noon during the summer, when solar UV light is at its strongest. But where you are located on the earth matters as well.  

According to a study in the Journal of Postgraduate Medicine, when you compare summer in the Northern hemisphere versus the Southern hemisphere, the Northern hemisphere is 1.7% farther away from the sun than the Southern hemisphere, and the intensity of UV light decreases by approximately 7%. Quebec in the summer, for example, will have a lower risk of snow blindness than Madagascar in the summer. 

High altitudes also make a difference because there is less distance for the light to travel and the thinner atmosphere filters less UV radiation. According to the World Health Organization, UV levels increase by 10% to 12% with every 1,000 meters increase in altitude. Cloud cover, latitude and ozone levels are additional factors determining how much UV light reaches your eyes. 

“Skiers in New England can get away with skiing with just sunglasses in fair conditions on a sunny day,” Weinstein said. “Once the wind kicks up stirring snow and other particles, goggles will be needed to protect your eyes from micro-debris damage as well as harmful UV rays. Goggles provide better protection against UV light, wind and debris.” 

Symptoms and Recovery 

Just like a skin sunburn, by the time you notice the damage to your eyes, it’s too late. According to The College of Optometrists in London, 6 to 12 hours after exposure, the eyes become red, painful, watery and sensitive to light. Additional snow blindness symptoms include: 

• Burning eyes 
• A gritty feeling, like there is sand in your eye 
• Blurred vision 

• Red and swollen eyelids 
• Headaches 
• Glare and halos around lights 

To aid recovery, a doctor may prescribe eye drops or pain relief tablets to make the eyes more comfortable while they heal. A doctor may also recommend:  

• Staying indoors to let your eyes heal before going back outside 

• Keeping eyes well moistened with artificial tears 
• Placing a cool, damp washcloth over closed eyes 
• Removing contact lenses 

An Ounce of Prevention 

Alaska’s indigenous people knew the dangers of the sun. In the Smithsonian, you’ll see snow goggles made out of a piece of bone or wood with a strip cut into the center to reduce glare and protect eyes from injury. Today, outdoor adventurers can stop by a sporting goods store to purchase full coverage, mirror-coated sunglasses, glacier goggles with polarized lenses or tight-fitting snow goggles.  

Here are a few additional suggestions to keep your eyes safe from snow blindness: 

• If you participate in water or snow sports, invest in quality, wraparound sunglasses with photochromic lenses (lenses that darken upon exposure to light).  
• Wear sunglasses that block out 100% of UV rays whenever you plan to be outdoors for more than three hours at a time. 

• Remember reflective glare from sand, water and snow can still harm your corneas even when the weather is overcast. 

As a rule, the view may be gorgeous but please keep those goggles or sunglasses on at all times. 

How Global Rescue Can Help 

Traveling to a sun-drenched or snow-covered location? Sign up for a travel protection services membership. Whether you are on the top of Aconcagua or in the middle of the Indian Ocean, you’ll have access to 24/7/365 medical advisory services, field rescue from the point of injury, and medical evacuation to the nearest hospital or home hospital of choice. And even if you’re skiing at your local mountain, Global Rescue’s memberships now include Local Field Rescue services within 100 miles of your home.