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After more than two years of covid-19, another epidemic may be the last thing anyone wants to read about. If so, then apologies in advance, for in this week’s episode of “ Babbage”, our podcast on science and technology, we investigate the rapid rise of short-sightedness or, to give it its technical name, myopia. You can also read my reporting on it.
The numbers are stunning. In some parts of East Asia—think Hong Kong, South Korea, Taiwan and parts of China—more than 80% of school-leavers need glasses to see properly. Fifty years ago, the share was 25% or less. The problem is less acute in Europe and the Americas, but even there the best numbers we have suggest that between 20% and 40% of young adults need their vision corrected. That is roughly an order of magnitude higher than what scientists think is the “natural” rate of myopia.
The rapid rise in Asia in particular has sunk the old consensus that myopia is mostly genetic. Instead, the strongest association seems to be with education. The more years of it you get, the higher the risk. And the more diligent a student you are, the more likely you are to be myopic too.
Of course, no one is arguing that learning new things directly causes short-sightedness. The culprit seems to be too much time spent indoors, where the lighting is dim. Studies on animals now strongly suggest that frequent exposure to bright sunlight is necessary for young eyes to develop properly and to be able to see well in adulthood. That is also thought to explain why myopia is so common in East Asia, where kids often follow a full day of schooling with several hours of private tutoring.
Does it matter? Anyone who wears glasses or contact lenses will tell you they are annoying. But East Asian governments have come to see the myopia epidemic as a public-health problem, too. Being short-sighted predisposes you to more serious sight problems in later life, some of which are untreatable and can cause blindness. The risk is especially high among those with severe myopia—a threshold already crossed by 10-20% of school-leavers in some East Asian countries.
Fortunately, the cure seems straightforward. Booting kids outside exposes them to more sunlight. Trials in Taiwan, where children are forced to spend more of the school day outdoors, have cut the numbers who go on to develop myopia. And a range of new technologies, including contact lenses designed to reshape the eye, and eye drops made from atropine (the toxin in deadly nightshade), seem able to slow progression once it has started.
Finally, it’s worth pointing out something else. The one thing that does not seem to be responsible for the epidemic of myopia is the proliferation of screens. The rise in short-sightedness in East Asia began decades before smartphones, laptops and e-readers had been invented. So if you decide to read my reporting on myopia, please do so on the device of your choosing. But afterwards, if you have kids, send them out into the garden. As your own mother no doubt told you, it’s for their own good.
Elsewhere in The Economist we present the obituary of a mastodon; examine plans by Alphabet (Google’s parent company) to become a force in health care; and our colleagues in the Films team tell us how scientists are
searching for alien life.
Thank you for reading this edition of Simply Science. If you have any thoughts or feedback about this newsletter or The Economist’s science coverage in general, feel free to contact us at: alok@economist.com. | | |
What’s on our radar: Nuclear waste disposal
A closer look at recent science news | | |
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More than 260,000 tonnes of spent nuclear fuel has accumulated in 33 countries since the first nuclear power station began operations in 1954. It produces doses of radiation that are fatal after short periods of direct exposure. The materials also have long half-lives, which mean it will take a few hundreds of thousands of years (longer than Homo sapiens has walked the Earth) before their radioactivity falls back to roughly the same level as that of the original uranium ore. The vast majority of this waste is currently packed into temporary storage, often within or near the power stations that generated it. But there is a fairly straightforward, better way of dealing with it: deep burial, several hundred metres below ground.
Finland is the first country to try this out properly, by building a deep geological storage facility, on the island of Oikiluoto, a couple hours north of Helsinki. Onkalo (Finnish for “cavity”) is basically an oversized lift shaft that connects a radioactive assembly line at the surface to several hundred kilometres of galleries carved out of the granite bedrock, 450 metres underground. When the site begins operations in the mid-2020s, room-sized robots working along the assembly line will seal the spent fuel into vast copper capsules which will then be lowered down the shaft. There, they will be picked up by remotely operated vehicles that will ferry the capsules to their final resting place. The Economist
’s environment editor recently paid the facility a visit—you can read about what she found in this week’s Science section. | | |
This week a fisherman on the Mekong river in Cambodia caught the biggest freshwater fish ever recorded—a 300kg stingray. The fish was later released. | | |
What our science journalists are reading | | |
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How AI can help to meet climate goals (IEEE Spectrum) |
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A chance encounter with a rare phenomenon called a milky sea connects a sailor and a scientist (Hakai) |
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The record-breaking Voyager spacecraft begin to power down (Scientific American) | | |
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