-The EYE Digest-
Snow Blindness - Can I Really Go Blind from the Snow?
In short, no, snow blindness doesn’t actually cause blindness, but read on for more information!
What is it?
Snow blindness is also known as photokeratitis. “Keratitis” means inflammation of the cornea (the sensitive, clear part of the eye in front of the colored iris), while “photo” means light. Snow blindness is when the cornea becomes inflamed after being overexposed to light, or more specifically ultraviolet (UV) light. To put it simply, snow blindness in a sunburn on your eye!
What causes it?
The most common cause of snow blindness is just as you may have guessed…snow! More specifically, it is the UV light that is reflected off the snow and into your eyes. Approximately 80% of the UV light that hits fresh snow is bounced back into the air and potentially into your eyes. This is significantly greater than sand or water which have UV reflectance of 15% and 25%, respectively. To make matters worse, many snow related activities such as skiing or snowboarding occur at higher altitudes where UV light is stronger – with every 1,000 ft of elevation from sea level, the intensity of UV light increases by 4%.
Snow, sand, and water aren’t the only sources of snow blindness/ultraviolet keratitis. Tanning beds and arc flashes from welding can also cause ultraviolet keratitis. When it is associated with welding, it is called a flash burn.
What are the symptoms?
Eye pain, irritation, and a foreign body or burning sensation are a few of the symptoms you can experience. Other symptoms include light sensitivity, watery eyes, red eyes, and blurred vision.
What is the treatment?
The treatment goals of snow blindness are first and foremost to prevent worsening by staying indoors or wearing UV eye protection and second, to keep the eye comfortable as it heals itself. Luckily, snow blindness resolves on its own within 24-72 hours. In the meantime it is advised to avoid rubbing your eyes and remove contact lenses.
Non-preserved artificial tears and lubricating ointments are recommended to act as a cushion between the sunburned cornea and the mechanical motion of your eyelid rubbing across the cornea. Artificial tears and ointments on a sunburned eye have a similar affect as putting aloe vera on your sunburned skin.
If the pain is still too much to handle, then over the counter pain relievers such as Tylenol or Advil can be used. Topical pain relieving eye drops (NSAIDS) can be prescribed by your eye doctor.
If the degree of ultraviolet keratitis is significant enough, your eye care provider may prescribe a topical antibiotic to prevent a secondary infection.
How do I prevent it?
Just like a sunburn on your skin, once you’ve become symptomatic,
you have already been in the sun for far too long. Fortunately, snow blindness is completely preventable by wearing snow goggles or eye masks with 100% UV protection. If you are at the beach, lake, or any body of water wearing sunglasses with 100% UV protection is recommended. The best type of eye protection is the type
that wraps around the face reducing the amount of UV light
that can reach your eye from the sides, top, or bottom of the frame. And remember, UV light is still present even on an overcast day, so when in doubt, where eye protection!
Welders are advised to wear welding goggles or welding helmets.
-Dr. Janelle Santa Maria
Dr. Janelle Santa Maria is an optometrist at Los Altos Optometric Group and contributing author and editor of The EYE Digest.
To contact her with questions or make an appointment call: (650) 948-3700 or send her an email: firstname.lastname@example.org