The pandemic may be behind the rise in nearsightedness in children, researchers revealed today.
Experts have long warned that this is because young people spend less time outdoors and more time watching television and playing video games.
However, scientists say Covid, which has forced millions of people to stay indoors, may have accelerated ‘vision deterioration’ in children.
According to the groundbreaking global analysis, one in three children are now short-sighted or have difficulty seeing things in the distance.
Globally, the number of cases of myopia (the medical term for nearsightedness) has tripled between 1990 and 2023, rising to 36 percent.
Experts have long warned that this is because young people are spending less time outdoors and more time watching television and playing video games.
The World Health Organization estimates that more than half of the global population will suffer from myopia by 2050, compared to a third today, due to increased time spent indoors and doing ‘near work’, such as spending more time on schoolwork.
Writing in the British Journal of OphthalmologyThe Chinese experts warned: ‘New evidence suggests a possible link between the pandemic and accelerated vision decline in young adults.’
Myopia occurs when the eyes become slightly too long, causing light to focus just in front of the retina instead of on it. This causes distant objects to appear blurry.
The condition often runs in families and is associated with focusing for long periods of time on close objects, such as books and computers, in childhood.
It is thought that around 20 million Britons and 137 million Americans have it.
The World Health Organization estimates that more than half of the world’s population will suffer from myopia by 2050. This is because people are spending more time indoors and doing ‘near work’, such as schoolwork.
But an earlier global review of the condition’s prevalence only included studies up to 2015.
To get a more accurate picture, researchers from Sun Yat-sen University in Guangzhou, China, analyzed 276 studies involving more than five million children from 50 countries.
Geographic variables were taken into account, they said.
The highest rates were found in East Asia, with 86 percent of children in Japan and 74 percent of children in South Korea diagnosed with myopia.
Russia ranks third with more than 40 percent of the affected countries.
By comparison, Paraguay and Uganda recorded some of the lowest levels, around one percent.
The UK and US were at around 15 percent.
According to the new research, the number of cases of myopia among children and teenagers is expected to exceed 740 million by 2050.
Research has also shown that girls are at higher risk than boys because they tend to spend less time outdoors in school and growing up at home.
‘Despite these known limitations and given the large sample size, our estimates of myopia prevalence are believed to be close to the precise number,’ they added.
Symptoms of this condition include sitting close to the television, complaining of headaches or tired eyes, and frequently rubbing the eyes.
British eye experts have long advised children to spend at least two hours outside every day, especially between the ages of seven and nine, to reduce the risk of short-sightedness.
It is not clear whether it is the presence of natural sunlight, the fact that children are playing sports outside, or the fact that children’s eyes focus on objects that are further away that makes the difference.
“There is something really beneficial about being outdoors for children,” says Daniel Hardiman-McCartney, clinical advisor to the UK College of Optometrists.
Myopia cannot be cured, but it can be corrected with glasses or contact lenses.
Special lenses can slow the development of myopia in young children by changing the way the eyes grow. However, these lenses are expensive.