Most people who are short-sighted could confirm that it’s surprisingly hard to notice what you can’t see. I found out I needed glasses as a teenager. My aunt was telling me about getting glasses for the first time, and what a surprise it had been to see the world in detail. She hadn’t realised it was possible to, say, make out the individual leaves on trees. She thought everyone only saw a blur of green foliage, as in a child’s drawing of a tree. We were in the garden. “Wait, what?” I said, mind-blown. “When you look at that tree there, you can see the leaves?”
I only discovered that my -6.5 prescription had become woefully inadequate when my husband took me out for a driving lesson, and I realised I couldn’t read any of the road signs.
At Specsavers, I asked Aaron Uraon, the pre-reg optometrist who wrote my alarmingly high new prescription, whether he had noticed that the pandemic meant more people than usual were coming to him with complaints about their eyesight. “100 per cent,” he replied. His patients were now spending the whole day looking at screens. They no longer had coffee breaks or meetings with colleagues; their working days were stretching from 9 to 5 to take up most of their waking hours. Their home offices weren’t set up properly, so the lighting was all wrong. They’d take a break from their laptops to look at their phones and then put away their phones to stare at the TV. And they were complaining of headaches, blurred vision and red, itchy eyes.
He identified two immediate problems. First, because screens flicker, though often imperceptibly, and we are worried about missing important information, most of us aren’t blinking properly. Rather than fully closing our eyes we are only half-shutting them, which causes dry eyes. Second, though our eyes are adapted to constantly focus and refocus as we observe our surroundings, we are spending most of the time focusing on a fixed spot not too far from our noses. This is causing eye strain. “It’s like if you were holding 2 kilo dumb-bells; you could do it for a while but after eight hours your muscles would start to get very fatigued and sore,” he said.
There is also a bigger, longer-term problem, which is that our modern lifestyles seem to be causing people to become ever more short-sighted. In the UK, the rate of short-sightedness among children has doubled in the past 50 years. In parts of east Asia the situation is worse and around 90 per cent of school leavers are short-sighted. The reason why any one person becomes short-sighted are complex, but some of the risk factors are stark: university graduates are twice as likely to be short-sighted as people who leave school at 16, presumably because the former spend more time with their eyes trained on books and computer screens.
In June a survey of 2,000 people commissioned by the College of Optometrists found that around one in five of them had noticed their vision get worse in lockdown and 32 per cent thought that spending more time behind screens was harming their eyesight.
Daniel Hardiman-McCartney, a clinical adviser for the College of Optometrists, told me that pandemic eye strain is unlikely to cause permanent damage in adults. He said it was impossible to know whether the deterioration in my eyesight was the result of a year of excessive screen time or something else. But he was worried about how lockdown might harm children’s vision.
“One thing we know absolutely is that as the eye is developing between the ages of six and 12, the more time you spend outside the less likely you are to become short sighted,” Hardiman-McCartney said. He recommends that children spend a minimum of 40 minutes outside each day and described it as a “real concern” that so many have been cooped up inside for most of the year.
A study of 123,535 children living in Feicheng, China, found that the prevalence of myopia among the youngest children, aged six to eight, was between 1.4 and 3 times higher in 2020 compared to 2015. The report suggested that the increased screen time and reduced time outdoors may have “worsened the burden of myopia” for this group.
“With children at this critical age group [between 6 and 12] we’re really concerned that lockdown may have created a situation where there are people who are short-sighted as a result of spending less time outside,” Hardiman-McCartney said.
For adults, he recommended the “20-20-20 rule”, which is to make sure that when you are at your desk you look up every 20 minutes and focus on an object around 20 feet away for at least 20 seconds.
The world will look clearer and your horizons will expand if you’re not completely absorbed by what’s happening on your computer or iPhone screen, which sounds like a metaphor but is quite literally true.