Scott W. Tunis MD FACS
Board Certified Eye Physician and Surgeon
Think about all the time, money and effort we as runners invest in protecting our bodies, muscles and joints from the physical demands of our favorite sport.
But how much time and effort do we spend protecting our most precious sense while we run? Is it just enough to throw on some sunglasses? Anything else to know?
Over a 35 year career of treating eye injuries and performing eye surgery I have seen my share of eye injuries that you could never imagine. It would be difficult for you to name any object, whether it be a projectile or not, whether it be sharp or dull, or whether it ever even gets near your eye that I have not seen cause a problem. Deer antlers, no less.
Thankfully, running is not a particularly hazardous sport with respect to eye injuries. The most common are foreign objects, such as sand or dust, kamikaze insects, and wayward tree branches in trail runners.
But aside from taking the usual precautions to avoid rare injuries, there are some other basic things you should know about running, eye health, and protecting your vision.
Sunglasses: What do I Look For?
A good quality pair of sunglasses will protect your eyes, first and foremost, from wind, dust, dirt, and mechanical injuries.
They should provide 100% ultraviolet protection. Prolonged UV exposure from light reflected off a body of water or a snow covered landscape can cause temporary corneal epithelial injury and blurred vision, so called “snow blindness”. Keep in mind, the UV protection on sunglasses is a clear coating and is not related to the darkness of the tint or color of the lens, so darker does not mean more protection.
Polarized lenses provide better vision in sunlight by reducing glare, improving clarity, and enhancing depth perception. Polarized lenses are probably a good idea if you want to have the best view of your terrain while putting one foot in front of another!
Your fit should be snug, so that there is no bounce, and the lenses should not sit too close to your eyes so as not to contribute to excess fogging.
Sweat in your eyes: What to do?
Despite your best efforts to stem the tide, so to speak, with a hat, a visor, or a bandana, tears which are high in salinity will sting and burn. Usually at the most inopportune times. This can’t hurt you.
But you can reduce the nuisance by using a minimum of cosmetics or skin cream around your eyes, which if washed in with tears will exacerbate the stinging. You should also choose water-based, rather than oil-based, skin moisturizers or sun block on your forehead.
Contact Lenses: Am I OK?
Most runners who require corrective lenses for good vision will opt for contacts rather than glasses while running. The main issue here is lubrication, particularly in cold or low humidity conditions, where dry eye and contact lens wear can lead to discomfort, blurred vision, or even worse. If you run in the winter with contacts, you might consider a carrying a lubricant drop in your pack.
Post LASIK: What to Know
A lot of runners have had previous LASIK surgery. It may take up to one full year for complete visual and physical healing after uncomplicated surgery.
Keep in mind if you were a long term exclusive contact lens wearer prior to LASIK, your eyes were protected from the external environment by the lenses. After LASIK, your corneas are exposed. It’s as if we took your shoes off and made you run barefoot… ouch! (for all except the barefoot runners!)
It may take several months for your corneas to “toughen up” and for hypersensitivity to subside. Protection from wind and dryness are even more important during this time.
For You Ultras: Ultramarathon-Associated Visual Impairment (UAVI)
Temporary, severe and reversible visual loss has been reported approximately 700 times in ultra marathoners due to corneal edema (swelling), presumably with an underlying cause of excess levels of lactic acid accumulating in the corneal stroma.
The risk factors which increase the likelihood of UAVI seem to be races over 50 miles and previous refractive (LASIK) surgery. 5% NaCl drops can rapidly reduce the blurred vision if used under medical direction.
Fortunately this is a rare condition which resolves. Its occurrence is not all that surprising… vision is not the only organ system stressed to its breaking point in ultramarathons.
The Good News
Running is without question one of the most beneficial forms of exercise in promoting and maintaining the health of your cardiovascular system, including the circulatory system of your visual pathways, and hence, protecting your vision. There is also good evidence that running lowers intraocular pressure and reduces the risk of glaucoma, a common disease with significant morbidity.
So get the right sunglasses, consider clear protection if you run at night,
Keep running, and enjoy the view!