A marathon runner temporarily lost sight in one eye when it froze as he was jogging in poor, cold weather. The 44-year-old man suffered from ‘wind-blindness’ – a condition in which the wind dries out the protective layer of tears covering the eye. This allows snow and hail to get into the eye, freezing its outer layer.
People do not blink as much in cold weather, meaning the eye isn’t thawed out with fresh tears.
The man came to a medical checkpoint at the end of the first stage of a marathon complaining of a sore left eye, cloudy vision and the feeling of having something in his eye.
Describing his case in the British Medical Journal case reports, doctors discovered he had frozen his left cornea, the clear outer layer at the front of the eyeball.
This led to scratches known as abrasions developing on the surface.
Parts of his left eye were swollen and his lens was visibly cloudy, doctors noted.
The medics immediately pulled the man out of the poor weather conditions until his the swelling went down and his vision recovered.
Any further cold and wind damage to his eye could have cause ulceration of the cornea, which can threaten vision if left untreated, they said.
There was intermittent hair and snow the day the man was running, with temperatures plunging from below 5°C to below zero.
Doctors warn marathon runners to wear goggles to protect their eyes while racing in poor weather conditions
There were also winds in excess of 80 miles an hour on the exposed ridges of the route, and the man was not wearing any eye protection like goggles, or any facial protection such as a peaked cap.
The man described his injury as ‘silent damage’ occurring during the race, which was a non-stop seven day ‘ultramarathon’ - a race lasting more than 26 miles (42 kilometres) - held in the UK.
While racing he felt no pain or damage to the eye and did not recognise the risk until too late, similar to the experience of frostbite, the doctors said.
He had been finding navigating in the dark difficult and had been tripping over his footing.
Initially he had assumed not being able to see in depth and his increased stumbling was due to fatigue and low blood sugar.
It was not until he reached the medical checkpoint he realised the problem was with his vision.
Writing in the journal, doctors warned of the dangers of the rise of ‘ultramarathons’ across challenging ground.
An ultramarathon, also called ultra distance, is any sporting event involving running and walking longer than the traditional marathon length of 26 miles (42 kilometres).
They said: ‘The UK has seen a big rise in ultra races over varied terrain. Weather conditions add another dimension to these races.
High wind speeds and cold temperatures may increase the attraction of certain races, but they present dangers to the participants which may not always be recognised.
They advised all runners to wear goggles in such races.
They said: ‘While the wearing of goggles is commonplace in winter activities such as skiing and mountaineering, it is less accepted as necessary by runners to prevent ocular injuries precipitated through prolonged exposure to high winds and sub-zero temperatures.
‘There is very little evidence in the literature concerning the risk of eye injury or “wind-blindness” in athletes, although it appears to be a well-known condition across running and ultra-marathon communities.’
WHAT IS WIND BLINDNESS?
High winds dry the front of the eye and reduce the protection offered by a layer of tears.
As particles such carried in by the wind, such as snow or hail, get into the eye.
The cornea, the clear outer layer at the front of the eye, becomes frozen.
People do not blink as much in cold weather, leading to abrasions, or scratches, forming on the cornea.
If ulcers form, this can affect vision.
Wind-blindness has previously been studied in military parachutists whose eye protection had failed during free fall.
There is usually no permanent damage when the eyes return to above-zero temperatures.
Source: BMJ Case Reports