Coronavirus lockdowns could have damaged the eyesight of thousands of people, scientists have warned.
Another study has discovered spending hours looking at screens can lead to short-sightedness, which causes distant objects to appear blurred.
And eye specialists in Singapore, Germany and Japan, behind the research, fear the Covid-19 pandemic may cause rates of the condition to spiral.
The doctors analysed data of 120,643 children and found ‘increased digital screen time and limited outdoor activities’ were linked to causing myopia.
And they wrote both factors ‘could potentially be aggravated during and beyond the Covid-19 pandemic outbreak period’.
Looking at screens more during lockdown could cause a spike in short-sightedness, according to a new study (stock picture)
Countries across the world adopted strict measures to strangle the virus, including blanket lockdowns that effectively banned socialising outdoors.
Such policies have led to children taking classes online, friends talking over Zoom instead of in real-life and people binge-watching TV.
The experts said ‘behavioural changes that arise from the growing dependence on digital devices may persist even after the pandemic’.
They wrote: ‘There is a possibility that a prolonged battle against the Covid-19 virus may lead to an increase in the incidence of myopia.’
The team warned the drastic measures may shape ‘long term behavioural changes conducive for the onset and progression of myopia’.
Health Secretary Matt Hancock has already said all GP appointments should be done over by phone or video unless there ‘is a compelling clinical reason not to’.
The study’s warning — based on reviews of older studies on myopia — was published in the American Journal of Ophthalmology.
Short-sightedness happens when eyeballs grow slightly too long so that light can’t focus on the light-sensitive tissue at the back of the eye properly.
Light rays end up focusing just in front of the retina and make objects in the distance seem blurry.
It often runs in families and has been linked to focusing on nearby objects, such as books and computers, for long periods during childhood.
The NHS says: ‘Ensuring your child regularly spends time playing outside may help to reduce their risk of becoming short-sighted.’
Experts warned children faced the greatest risk, given the controversial decisions to shut schools and make them rely on digital devices to learn.
Roughly 3.8billion people across the world currently have myopia. But it is estimated that 5billion people worldwide will suffer by 2050.
Governments around the world have already tried to curb spiralling rates in the past by encouraging children to spend more time outside.
In Taiwan, the government once encouraged schools to get students outside for two hours a day in a bid to cut spiralling rates of myopia.
But it is much harder to spend time outside during lockdown — first imposed in the UK on March 23 to tackle the Covid-19 crisis.
Health chiefs across the country told Brits to ‘stay at home, protect the NHS, save lives’.
Blanket advice wasn’t put into place in the US and different states imposed different measures.
But the Center for Disease Control still urges the public to ‘understand the potential risks of going out’.
UNESCO says 1.4billion students across the world have been affected by lockdown measures and have been forced to adopt digital and e-learning.
The review was led by experts at the Singapore Eye Research Institute, Germany’s Heidelberg University and the Tokyo Medical and Dental University.
One of the studies reviewed by experts — of 5,000 youngsters in the Netherlands —found a strong link between increased computer use and myopia.
Another study of 418 children in Ireland revealed that smartphone usage was also associated with myopia.
And one review of various studies that included 25,025 children aged six to 18 found spending less time reading may reduce the risk of myopia.
But according to the results, increased screen time wasn’t actually directly linked to myopia.
However, children gave self-reported measurements of screen time which could be biased and not accurate.
The World Health Organization recommends less than one hour of sedentary screen time for children aged between one and five every day.
The authors of the study, led by Dr Chee Wai Wong from the Singapore National Eye Centre, advise children spend two or three hours outside every day.
The team wrote: ‘The health benefits of outdoor activities and an active lifestyle should not be stifled by Covid-19.’