Friday, August 25, 2023

The World's Myopia Epidemic

I've been nearsighted all my life so I tend to take it for granted. But I will agree that it's not a normal condition, in the sense that it's a departure from baseline health. And it is becoming more common, but until I read this article, I hadn't realized just how common. 

The article focuses (sorry, couldn't resist) on Taiwan, where more than half of children were myopic, and the efforts of one doctor to determine the cause and find a way to prevent it. It turns out that it's possible to reduce the incidence of myopia in children by having them spend more time outdoors and this has been determined to work. 

Myopia, or what we commonly call nearsightedness, happens when the eyeball gets too long—it deforms from soccer ball to American football—and then the eye focuses light not on the retina but slightly in front of it, making distant objects appear blurry. The longer the eyeball becomes, the worse vision gets. Ophthalmologists measure this distortion in diopters, which refer to the strength of the lens required to bring someone’s vision back to normal. Anything worse than minus 5 diopters is considered “high myopia”—somewhere between 20 and 25 percent of myopia diagnoses around the world are in this category. In China, up to 90 percent of teenagers and young adults are myopic. In the 1950s the figure was as low as 10 percent. A 2012 study in Seoul found that an astonishing 96.5 percent of 19-year-old men were nearsighted. Among high schoolers in Taiwan, it’s around 90 percent. In the US and Europe, myopia rates across all ages are well below 50 percent, but they’ve risen sharply in recent decades. It’s estimated that by 2050, half the world’s population will need glasses, contacts, or surgery to see across a room. High myopia is now the leading cause of blindness in Japan, China, and Taiwan.

If those trends continue, it’s likely that millions more people around the world will go blind much earlier in life than they—or the societies they live in—are prepared for. It’s a “ticking time bomb,” says Nicola Logan, an optometry professor at the UK’s Aston University. She wasn’t the only expert I talked to who used that phrase. Because so much of Taiwan’s population is already living life with myopia, the island nation has already glimpsed what could be coming for the rest of us. And in a rare confluence, the country may also be the best place to look for solutions.



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