China’s myopia epidemic: why a simple solution is being ignored
Under pressure to perform academically, children are spending most of their time indoors, depriving them of the sunlight that allows their eyes to develop
“We didn’t pay much attention at the beginning, because we thought she just wanted to concentrate on the details of games she plays in the phone,” says Xi’s mother. But it turns out the 4½-year-old will have to wear glasses. She has myopia, something her young parents don’t think of as a problem.
“It’s just an aesthetic issue. She will have to get used to the spectacles. Many people even wear them without the lenses just for fun, so I don’t think there is anything to worry about,” her mother jokes.
Shanghai ophthalmologist Xu Xun disagrees. As one of China’s most respected experts in this field, he believes the prevalence of myopia has grown to worrisome proportions in the country.
“Myopia rates have shot up in the last two decades,” he says, as we speak in a conference room at the treatment centre. “According to our statistics, between 10 per cent and 20 per cent of primary school pupils start classes with myopia. Then the percentage rises to up to 50 per cent for secondary school students. In university, 90 per cent are short-sighted.”
Myopia – or short-sightedness – occurs when the eyeball is too long relative to the focusing power of the cornea and lens of the eye. Light does not focus on the retina as it should, making distant objects appear blurry. It is the most common refractive error of the eye and like the others, myopia’s severity is measured in dioptres ((a unit of refractive power measured in the negative, and which is written as D for short), the same unit used to measure the optical power of glasses and contact lenses. Kindergarten children are defined as having myopia at -0.6D, whereas adults officially become myopic at -1D. Four-and-a-half year-old Xi’s myopia has been measured at -1.5D.
The growing prevalence of myopia is not only a Chinese problem, but it is an especially East Asian one. According to a study published in The Lancet medical journal in 2012, by Ian Morgan, of the Australian National University, South Korea leads the pack, with 96 per cent of young adults (below the age 20) having myopia; and the rate for Seoul is even higher. In Taiwan, 85 per cent of young adults are myopic, according to the study, and in Singapore, the figure is 82 per cent.
About 30 per cent of Hongkongers born before 1950 are myopic, according to a report by the Centre for Myopia Research at Polytechnic University, but that rate shoots up to 70 per cent for those born between 1950 and 1980. And, The Lancet study suggests, at least 87 per cent of our young adults are short-sighted.
By contrast, about 30 per cent of young adults in countries such as Britain are myopic.
“Alarmingly, more than 80 per cent of the entire adult population will be myopic within the next 30 years,” say the PolyU researchers, and their study also found that the prevalence of myopia in Chinese children is noticeably higher than among other ethnic groups in Hong Kong.
What most troubles Xu, director of the Shanghai Eye Disease Prevention and Treatment Centre and chairman of the Department of Ophthalmology at the Shanghai Jiao Tong University Eye Institute, about the trend in China is that 20 per cent of those between 20 and 30 years old develop high myopia, defined as being greater than -8D.
“That percentage is five times the global average and we believe up to half of them will eventually lose all or most of their sight,” he says. “Glaucoma, macular degeneration and retinal detachment are all more common among those patients suffering high myopia. And especially the first two become hard to detect without proper checks. Most sufferers seek medical advice when their vision is already too low and the situation is irreversible.”
The narrow corridors of the Shanghai Eye Disease Prevention and Treatment Centre are crowded on a recent Saturday as hundreds of children are having their eyesight checked in a dozen rooms. Some as young as 10 are already at the -5D stage.
Extreme academic pressure is put on kids and teenagers. We request good results even if that means keeping them indoors for most of their childhood
“In our experience, children with myopia add an average of 0.75D per year if concrete measures are not being taken,” says Xu. “And they aren’t.”
But why are Asian children particularly prone to myopia? Although the question tends to create a heated discussion among doctors, Xu doesn’t hesitate when answering.
“First of all, it’s not genetic. We’ve done many studies and that is something we are sure of.
“It’s a quite recent phenomenon. In the 1960s, only 20 per cent of the Chinese population was short-sighted. We can argue checks were not so common at that time, but the gap is still large. And genetic changes take much longer to shape. Plus, myopia is mostly prevalent in urban areas, while the rates in the countryside are noticeably lower.”
“On the one hand, extreme academic pressure is put on kids and teenagers. We request good results even if that means keeping them indoors for most of their childhood. And we know that the lack of natural light increases the chances of developing myopia.”
Indeed, a group of researchers at Australia’s Brien Holden Vision Institute found that myopia progression in Chinese children is up to 40 per cent slower in summer, when they are exposed to more sunlight, than in winter. Another group of Australian doctors found that the prevalence of myopia among ethnic Chinese children in Sydney is significantly lower (at 3.3 per cent) than among those in Singapore (29.1 per cent), where youngsters spend much less time outdoors.
Furthermore, Chinese scientists analysed the data from 681 children in Beijing and concluded in a study published by the American Academy of Ophthalmology that myopia increases in proportion to time spent studying. Bright outdoor light stimulates the release of the retinal transmitter dopamine, which blocks the axial growth of the eye and inhibits myopia.
“On the other hand, new technology used both for studying and for entertainment requires our eyes to concentrate on a small surface for a long period of time,” Xu says. “Although we are still studying the concrete effects of mobile devices on our vision, we believe the lower blinking frequency may also contribute to the deformation of the eye.”
China is not a place for kids to play. Cities are built for cars and playgrounds are for the elderly
Only a handful of the 150 inhabitants of Tanda, a small town in central Shanxi province, need spectacles. And most of those who do so are senior citizens, who have trouble seeing objects up close, which has nothing to do with myopia.
A few of the children have developed short-sightedness, but the fact that the vast majority haven’t seems to support Xu’s theory because, even if most of them live in mountain cave homes, they spend almost all of their time outdoors, and still play with real toys – or animals, because many families here herd sheep and goats.
“Our way of life is simple, but I believe it’s still healthier than in the city,” a teacher says before asking for help in repairing the school’s only computer.
About 1,500km to the south, in Yunnan province’s lush Xishuangbanna region, a teacher in a small village tells a similar story. “People here are poorer and, therefore, eye checks may not be as widespread as in the city,” says Ding Fenghui. “Some parents may even think glasses are expensive, so they would rather let their kids go without them unless they become indispensable. Still, among the 30 students in my class, only two have slight myopia.
“If you go to Jinghong – the region’s biggest city, about three hours’ drive from the village – the number is much higher. And some colleagues in Kunming, Yunnan’s capital, tell me almost every kid wears spectacles. I’m sure it has something to do with the way of life, but nobody seems to care.”
In Liyang, a medium-sized city in the eastern province of Jiangsu, the Jiang family adheres to a modern urban lifestyle. Neither of the daughters see much natural light, burdened as they are with classes and extracurricular activities that take place indoors. And when they arrive home, well past sunset, both reach for electronic gadgets. Siqi, four, loves the iPad; Enqi, seven, already has her own smartphone.
“We think they need to learn as much as they can, because our society is very competitive,” says their mother, Hu Yan.
Hu says she feels a bit sad “because they seldom have the chance to play outside and have got almost no friends”, but safety is a big concern: “You hear so many stories of abducted kids and see so many videos of terrible accidents in the streets. China is not a place for kids to play. Cities are built for cars and playgrounds are for the elderly.”
When we visit, the exercise machines in the central playground of the modern compound where the family lives are being used by senior citizens. No youngsters are in sight.
“Children need to study,” Hu says, dismissively. Apart from regular classes at school, and piano and English lessons, Enqi spends about 12 hours a week doing homework, more than double the average in European Union countries.
The games the Jiang daughters are allowed to play on their electronic devices are mostly educational – maths quizzes, crosswords, natural sciences – so there is little rest for them. Nor for their eyes. Both have developed myopia. Siqi does not yet need glasses but Enqi will soon reach the -3D stage.
“Doctors tell us that is common and that the myopia will eventually stop growing with age. I don’t see any problem; we also wear glasses,” Hu laughs.
Nevertheless, the school the girls attend does seem concerned. Every school day starts with a 10-minute set of eye exercises, known as “yanjing baojian cao”, which have been compulsory throughout the country since 1949 and the beginning of the People’s Republic. The exercises consist of five routines based on traditional Chinese medicine principles and include massages around the eyes.
Many scientists, however, consider the exercises useless. Stanford University’s Rural Education Action Programme tracked the progression of myopia in children over a nine-month period in 2012/13 in 252 participating schools in China. One hundred and forty nine had their students perform the eye exercises regularly while the others did not. The result was clear: myopia rates increased in both groups at the same pace.
“First of all, the massage has to be done in a very precise manner, pressing on tiny points in the face,” says Xu, the ophthalmologist, who is choosing his words carefully. “That is something we can’t expect children to do properly. And there is no scientific evidence to support the benefits of the exercise apart from its relaxing properties.”
Xu also dismisses an initiative that has been launched at some schools in Guangdong province: having transparent panels installed in roofs and walls, to allow more natural light into classrooms. “It’s impractical [especially in multi-storey buildings]. Can you imagine how much that would cost if implemented countrywide?”
Some doctors have proposed that instead of napping after lunch, children should be encouraged to take part in outdoor activities, but parents are reluctant to see that change.
If my daughter doesn’t study hard, she’ll be left behind. If her myopia is high, she can always have corrective surgery
Last September, the Shanghai city government started pioneering a much simpler solution, one that might actually work. It’s making it mandatory for children to have 80 minutes of outdoor activity a week while at school.
“That’s 20 minutes more than the rest of the country, so we will be able to analyse the difference and determine whether it should be extended further or not,” says Xu.
Studies suggest that every 40 minutes of outdoor activity per day decreases the chances of developing myopia by 9 per cent. Still, Xu concedes, few are in favour of this measure.
“Teachers want 40 minutes, at most, because they have to take care of the children during that time and are afraid of the responsibility. On the other hand, parents even think 20 minutes is too long.
“We believe two hours a day would be the optimum,” he smiles.
Ke Bilian, an ophthalmologist with the Shanghai Eye Disease Prevention and Treatment Centre, shares Xu’s opinion. Her responsibilities include explaining the dangers of myopia to parents and teachers, but most don’t take her seriously.
“Fortunately, we managed to get the approval of 93 per cent of the parents in the schools that are taking part in the 80-minute outdoor programme,” she says.
Unfortunately, both Ke and Xu concede this measure will only slow the rate at which myopia grows, not stop it.
Xu himself is an example of how difficult it is to fight the problem. At 56, the doctor doesn’t need glasses.
“I grew up during the Cultural Revolution. We seldom studied at that time. We just played with friends in the countryside,” he says. “But I was fortunate enough to take the gaokao [national university entrance exams] in 1978 and go to university. At that age, my eyes were almost fully formed.”
His son, however, had myopia measuring -2D when he entered high school, and went to the university with -5D.
“Even if my wife and I knew the consequences, we also pressured our child to get the best academic results – because we know how cruel life can be in today’s China without success.”
For most parents at the Shanghai Eye Disease Prevention and Treatment Centre, myopia is the lesser of two evils.
“If my daughter doesn’t study hard, she’ll be left behind,” says a mother who prefers not to give her name. “If her myopia is high, she can always have corrective surgery, like I did a few months ago. It’s fast, painless and works miracles.”
Indeed some parents already ask doctors if they can perform the procedure, Lasik, on children as young as 10, even though it is not recommended for eyes that have not yet fully formed.
And Xu warns that “in the future, blindness rates can increase in Asia even if new medical treatments improve”, largely because the problems associated with high myopia are difficult to detect before it is too late to treat them effectively.
“The government can only do so much,” says Xu. “We believe increasing outdoor activities is a good step forward, but it won’t be enough unless parents and society as a whole realise that myopia is a serious threat to health.”
