If you’ve ever had a sunburn, you understand the discomfort that goes along with it — the irritation, dryness, pain, redness, and itchiness. Snow blindness is a form of photokeratitis. (Learn More) It is very much like getting a sunburn on your eye.

Just like a regular sunburn, snow blindness is caused by exposure to UV (ultraviolet) light. It is caused by that light being reflected off snow or ice. (Learn More)

You generally won’t feel the effects of snow blindness until your eyes have already been damaged by UV light. Symptoms can range from mild irritation to significant pain and vision issues, depending on the severity. (Learn More) The longer your eyes are exposed to light reflected off ice and snow, the worse the snow blindness and side effects will be.

Snow blindness can be prevented by protecting your eyes from UV light reflection with protective eyewear. (Learn More) Typically, snow blindness will clear up on its own. The best thing you can do is rest and take care of your eyes while you recover. (Learn More)

Snow Blindness Basics

Photokeratitis is when the outer layer of your eye (the cornea) gets inflamed. This is caused by exposure to UV light.

Snow blindness is a common and extreme form of this condition that happens when your eyes are directly exposed to UV light reflected off snow or ice, typically at high elevations. It is most frequently seen in mountaineers, climbers, snowmobiles riders, snowboarders, and skiers.

You can also get photokeratitis from sunlight that is reflected off water or sand, from looking directly at a solar eclipse without eye protection, or from welding without the proper equipment.

Some medical conditions or medications can increase your risk for photokeratitis. People with light-colored eyes are more prone to it.

 

Causes of Photokeratitis

When snow is fresh, it can reflect nearly 80 percent of UV radiation directly back at you. This light can go into your eyes if they are not protected. The damage can occur quickly. Similar to a skin sunburn, you won’t realize the damage is occurring until it’s too late.

Snow blindness can also be caused by severe drying of the eyes or freezing of the cornea due to extreme temperatures. It is most common in high elevations since the air is thinner and there is less UV protection as a result.

The UV light kills off the outer cells of your cornea. These cells typically regenerate quickly (within a timespan of a few days), and your eyes can usually heal themselves.

Symptoms of Snow Blindness

The symptoms of snow blindness are similar to the symptoms of a skin sunburn, but they affect your eyes and include some vision issues. Symptoms range from mild to significant, depending on how long your unprotected eyes were exposed to the UV light.

Symptoms of snow blindness can include:

  • Eye irritation.
  • Persistent pain.
  • Redness and swelling.
  • Watery eyes.
  • Headache.
  • Blurry vision.
  • Twitching of the eyelid.
  • Sensitivity to light.
  • Seeing halos around lights.
  • Feeling like there is grit in your eyes.
  • Constricted pupils.

With a mild case of snow blindness, your eyes will be bloodshot and feel teary. With more severe cases, they can swell shut and feel “gritty.”

Your cornea begins healing right away, and the damage can be overturned in 12 to 48 hours on average. With more advanced cases, it may take a little longer than a few days for your eyes to return to normal. In severe cases of snow blindness, you may also experience temporary vision loss and color changes in your vision.

Snow blindness is a reversible condition. In extreme cases, you can experience chronic issues with tearing and eye irritation, but most of the time, there is no long-term damage.

 

How to Prevent Snow Blindness

Snow blindness is a completely preventable condition. To protect your eyes from UV light as well as freezing and dry conditions, wear goggles or sunglasses that block 99 percent (or more) of UV rays. Protective eyewear can block the UV rays from reaching your eyes.

Goggles can also keep the wind and extreme cold from impacting your eyes. Welders should always use a welding helmet. When you are at the beach, consider a wide-brimmed hat as well as sunglasses. Never look directly at the sun.

When choosing protective eyewear for extreme conditions, look for enclosed goggles or sunglasses with a wraparound style frame. These should be close fitting. Sunglasses made for extreme conditions, such as glacier glasses, usually have darker lenses, side covers, and better filtration for visible light.

Wear protective eyewear when you are in ice and snow, particularly at higher elevations, such as up in the mountains. You should wear this eyewear in all weather conditions, even when it is overcast. UV light can still get through the clouds and burn your eyes.

 

How to Treat It

Since your eyes are able to heal themselves from snow blindness, you can usually take care of the issue at home. Here are some tips for treating the condition:

  • If you wear contacts, take them out right away and rest your eyes.
  • Get out of the sun as soon as possible and stay in a dark room.
  • Hold a cool, damp cloth over your eyes.
  • Use eye drops like artificial tears to lubricate your eyes as needed.
  • Take over-the-counter (OTC) pain medications, such as ibuprofen or acetaminophen.
  • Place soft gauze over your eyes to allow them to rest.
  • Avoid rubbing or touching your eyes.

If you are up in the mountains and out in the elements when you notice symptoms of snow blindness, remove yourself from the situation as best you can. Get out of the cold and away from light. Give your eyes a day or two to rest and recover before resuming your normal activities.

Since symptoms don’t show up right away, you will likely not notice the damage to your eyes until much later — often well after snow blindness has set in. At this point, you will want to keep the damage from getting worse and treat the condition as soon as you notice it. The first step in treating snow blindness is to manage the associated pain and irritation, and protect your eyes to prevent further damage.

 

When to See a Doctor for Snow Blindness

If your symptoms persist beyond 48 hours and your eyes don’t seem to be getting better, it is time to seek a doctor’s help. You may have a more extreme case of snow blindness or another underlying eye condition that needs treatment. In some more significant cases of snow blindness, your ophthalmologist or eye doctor will prescribe antibiotic eye drops to help your eyes heal.

If in doubt, seek treatment. More comprehensive care may be needed, and it’s important to get medical attention in a timely manner.

 

References

Ultraviolet Radiation (UV). World Health Organization (WHO).

How to Treat Snow Blindness. (February 2017). Backpacker.

What Is Photokeratitis ­— Including Snow Blindness?  (January 2020). American Academy of Ophthalmology (AAO).

Snow Blindness. (February 2014). American Academy of Ophthalmology (AAO).

What Is Snow Blindness & How Can You Prevent It? (January 2020). University of Utah.