Britain is experiencing an epidemic of myopia, with 27% of adults and 20% of teenagers under 16 diagnosed and numbers likely to rise further, scientists have warned.
In a study scientists from University College London (UCL) also found 54% of people aged over 40 have refractive errors — eyeball distortions that blur their vision in some way.
That compares with myopia rates of just 10% in the 1960s, suggesting the condition is one of Britain’s fastest-growing health problems.
Other research shows childhood myopia has also grown more common, affecting 20% of young teenagers — double the rate of the 1960s.
A third study, from King’s College London, looking at 60,000 people across Europe, was even more alarming, suggesting 47% of 25 to 29-year-olds suffer from myopia.
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Experts say a key cause is a failure to spend time outdoors, where eyes benefit from greater light levels and focal distances, linked to more time spent reading books and screens. Such increases mean myopia should be declared a serious threat to public health, say the UCL researchers, who were led by Phillippa Cumberland of the Great Ormond Street Institute of Child Health.
“Our findings confirm that, within the ethnically diverse and ageing UK population, refractive error is a major public health issue and indicate the burden can be anticipated to increase over time,” they wrote in a research paper.
“It was very rare to see an under-10-year-old going myopic, but not now
The scientists used eye tests conducted on 107,000 people to seek the cause of the increase. One clue lay in education levels: 34% of people with degrees were myopic, while only 13% of people with no qualifications were affected.
Ethnicity was also a factor: about 47% of UK adults of Chinese ancestry were myopic, far more than in any other group. This fits with research from Asian countries such as South Korea, where 97% of 19-year-old males are myopic. That trend has coincided with a rise in educational expectations, which means the young spend far more time reading. This might suggest myopia is linked to working with screens and books, but researchers favour a subtler interpretation.
“It is clear that people who do a lot of close work are more often myopic,” said Nicola Logan of Aston University’s ophthalmic research group. “However, the cause is not just the close work. The real impact is from not going outdoors. People who read or look at screens a lot are protected if they also spend time outside.”
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Such findings will be discussed at the International Myopia Conference at Aston this year and could change the advice given to children such as Millie Hopper, 10, from Reading. She has worn glasses since she was five and is advised by her optician to take regular breaks from books and screens. She has also taken up swimming and dancing. “My time is balanced between reading and exercising now,” she said.
Research suggests children like Millie should spend at least two hours a day in bright daylight and that most young children have good vision and will keep it if the cornea, lens and eyeball grow in a co-ordinated way — so images focus on the retina. Such co-ordination should be achieved by nerve systems around the eyes, but if it fails, the eyeball can grow too long, meaning images are focused short of the retina — in other words, myopic vision.
“The brightness of the light children are exposed to is important in co-ordinating growth,” said Logan. “Daylight is far stronger than indoor light and it stimulates dopamine release from nerves in the eye. Dopamine may control eyeball growth, helping keep it the right length.”
The fear is the myopia epidemic could lead to increases in other conditions. The lengthening of the eyeball in myopia also stretches the retina — raising the risk of glaucoma, cataracts and detached retinas.
“It was very rare years ago to see an under-10-year-old going myopic, but not now,” said David Barker, of Rawlings Opticians in Croydon, south London. “Now I routinely talk to parents of young children to encourage outdoor play.”
