Why Short-sightedness Is On The Rise

107

  • Soaring rates of short-sightedness in children are alarming parents and doctors.
  • In children, it can hurt their ability to learn in school and enjoy daily life.
  • The phenomenon is being witnessed around the globe.

In the late 1980s and 1990s, parents in Singapore began noticing a worrying change in their children. On the whole, people’s lives in the small, tropical nation were improving hugely at the time. Access to education, in particular, was transforming a generation and opening the gates to prosperity. But there was a less positive trend, too: more and more children were becoming short-sighted. Today, Singapore has a myopia rate of around 80% in young adults, and has been called “the myopia capital of the world”. What happened in Singapore now appears to be happening all over the world. In the United States, about 40% of adults are short-sighted, up from 25% in 1971. Rates have similarly soared in the UK. Myopia has risen dramatically among children in China to reach 76%-90% among older school children. 

Why Is It Happening?

Genetics play only a small part. While a family history of myopia raises the risk of a child developing it, a purely genetic case of myopia is rare, says Neema Ghorbani-Mojarrad, a lecturer at the University of Bradford in the UK and a registered optometrist. Instead, lifestyle factors are thought to be more significant, in particular, a lack of time outdoors, and focusing on close objects for an extended period through an activity like reading. These factors help explain why one otherwise thoroughly positive trend in children’s lives has unintentionally worsened the spread of myopia: education. Of course, education in itself – in the sense of discovering the world, and empowering oneself through knowledge and skills – does not cause poor eye health. In fact, education is associated with many positive, measurable health effects.

The Education Anomaly

Ghorbani-Mojarrad and his colleagues studied the effect of education, as measured by school years, on myopia, by investigating the impact of the UK’s raising of the school leaving age from 15 to 16, in the 1970s. “There’s literally a bump in the chart for the extra year of school. Now that the leaving age is 18 in the UK, I wonder whether we will find the same thing again” he says. To understand this surprising link, it helps to parse how myopia develops in the first place. Most newborn babies begin life long-sighted. Within the first year of life, the eyes naturally develop and the long-sightedness reduces to the point of their vision becoming almost perfect. However, in some cases the eyes do not stop growing and short-sightedness develops. “Everyone has a finite amount of retina, and if the eye continues to grow, it’s like trying to scrape the same amount of butter on a larger piece of bread” says Ghorbani-Mojarrad. 

In Singapore, which has undertaken some of the longest-running research on childhood myopia, experts have reached a similar conclusion. The paradox is, of course, that reading is good for children – measurably so. Literacy, and schooling more generally, is crucial for children’s wellbeing, and missing out on them can cause lasting damage. This complex problem – myopia as a bad side effect of an otherwise positive trend – also shows up in another area: income levels. Like education, a higher income is generally associated with greater wellbeing in children – but not when it comes to eye health. Instead, myopia is associated with higher socioeconomic status.

Impact Of Lockdown

Because of the legacy of the lockdowns, China’s biggest concern at the moment is for children aged between four and six. “We’re worried that due to Covid-19, children are spending even more time indoors and that rates have gone up” says Chia. “We’re waiting for our data to find out.” Data from China already shows that the lockdowns did in fact deal a blow to young children’s eye health. One study compared myopia rates among children, measured by annual screenings. Before the pandemic, in the years from 2015-19, the highest myopia rate measured among six-year-old children was 5.7%. In June 2020, after 5 months of home confinement, researchers measured children’s eyesight in that age group and found that the rate that shot up to 21.5%. Due to pandemic lockdowns, myopia is also becoming a concern in countries that were not much troubled by it before. This can be particularly noticeable in countries where children generally roamed outdoors before the pandemic – but found themselves suddenly confined.

Healthy Eyes For a Healthy Life

In many parts of the world, providing an ordinary pair of glasses can be life-changing. Congdon has been working in China since the early 1980s, together with ORBIS International, a charity that has provided low-cost glasses to 2.5 million children in China and India. He undertook the first trial to find out whether glasses would improve educational outcomes. His study of 20,000 children in Guangdong, China found that the impact of giving a $4 (£3.70) pair of glasses outstripped the impact of parental education or family income. The most effective, evidence-based prevention strategy is also surprisingly low-tech, and applies to all countries regardless of their wealth or resources: more time outdoors.

In Singapore, outdoors time at preschools was doubled to one hour as part of the broader national myopia-fighting strategy. Exams for the youngest students have been scrapped, to reduce the time spent doing homework. Ultimately, a child’s eyesight is part of their general wellbeing. We don’t just want the focus to be on the eyes: it’s about the whole body and good mental health. 

Did you subscribe to our daily Newsletter?

It’s Free! Click here to Subscribe

Source: BBC

 

LEAVE A REPLY

This site uses Akismet to reduce spam. Learn how your comment data is processed.