Get full access to Outside Learn, our online education hub featuring in-depth fitness, nutrition, and adventure courses and more than 2,000 instructional videos when you sign up for Outside+ Sign up for Outside+ today.
Sticky, itchy, painful, bloodshot eyes. Swollen lids. Pus. Eye problems in the wilderness are often gross, sometimes dangerous, and always inconvenient. It’s difficult to practice ophthalmology in the backcountry, so they can be hard to resolve without evacuating. The good news: It’s easy to avoid some of the most common problems in the first place.
The most frequent wilderness eye complaint is corneal abrasion, or superficial scratches in the eye’s clear outer layer, whether from dirt or dust, an errant branch, or some other foreign body. Abrasions can be painful, but are thankfully short-lived. There’s no real threat to vision here, but minor traumas like this eventually warrant a thorough exam to rule out deeper damage. Wearing sunglasses or other eye protection in risky situations (like bushwhacks or windstorms) can offer an extra layer of security.
Mountain travel comes with some additional risk, most notably exposure to ultraviolet light at altitude. Light reflected off snow can cause UV keratitis, better known as snow blindness. Along with scurvy and frostbite, snow blindness plagued Antarctic expeditions in the late 19th century. Alexander Macklin, one of Ernest Shackleton’s surgeons, described “a prickly sensation of grit in the eyes, which becomes painful in strong light…with heavy discharge and total blindness.” It can take 24 to 48 hours to heal, and cause extreme discomfort (and difficulty orienting yourself) during that time.
As those early polar explorers realized, UV light reflected off of snow can cause temporary vision loss even on overcast days. While they resorted to stylish old-school goggles with little slits to allow light in, these days a good pair of glacier glasses with side shields offers better protection.
Red eyes can also be due to allergy, inflammation, or infection. Sometimes, viral or bacterial conjunctivitis—known as pinkeye—spreads rapidly when travelers are in close quarters, like tents or lean-tos, with limited hygiene. Bacterial conjunctivitis leads to disgusting goopy discharge and lids-stuck-closed-in-the-morning discomfort that warrants antibiotics. Equally important is cleanliness and isolation to avoid spread of infection. Check your lenses, too: Contacts that have been left in for way too long can lead to painful ulcers in the cornea.
In Shackleton’s day, explorers used topical cocaine to ease ocular pain, which in turn likely led to additional injuries, vision trouble and dryness, as well as who-knows-what other mayhem. For painful red eyes in the field, lubricating drops, avoiding contact use, and cool compresses may help. Other drugs, cocaine included, should be avoided unless specifically prescribed.
As with most other complaints, some eye emergencies warrant quick evacuation. If you have any significant trauma, painful or painless loss of vision, flashing lights, or floating spots in the visual field. Bonus tip: lost your glasses? Try looking through a pinhole punched in a card or paper – the narrow stream of light should allow for sharper vision through the hole while you grope your way to safety.
Christopher Tedeschi teaches and writes about wilderness and disaster medicine. He is associate professor of emergency medicine at Columbia University and an editorial board member for the journal Wilderness and Environmental Medicine. He enjoys hiking and biking near his home in the lower Hudson Valley.