Saturday, October 15, 2022

The Worldwide Surge in Myopia

 In 2014 an article was encountered which discussed a dramatic increase in nearsightedness in school age children in Asia.  It indicated that this phenomenon was the result of high-intensity educational practices that left too little time for play outside in the sunlight.  It was the lack of sunlight that disturbed the normal growth of the eyes.  Recently, another article appeared stating that this phenomenon had spread throughout the developed world, its cause was more complicated than merely too much studying, and it was producing a significant rise in dangerous eye conditions.  Sarah Zhang produced The Myopia Generation: Why do so many kids need glasses now? for The Atlantic.

Zhang provides this perspective.

“In East and Southeast Asia, where this shift is most dramatic, the proportion of teenagers and young adults with myopia has jumped from roughly a quarter to more than 80 percent in just over half a century. In China, myopia is so prevalent that it has become a national-security concern: The military is worried about recruiting enough sharp-eyed pilots from among the country’s 1.4 billion people. Recent pandemic lockdowns seem to have made eyesight among Chinese children even worse.”

For years it was assumed this effect was somehow specific to Asian populations.  Now the worldwide nature has become apparent.

“In the U.S., 42 percent of 12-to-54-year-olds were nearsighted in the early 2000s—the last time a national survey of myopia was conducted—up from a quarter in the 1970s. Though more recent large-scale surveys are not available, when I asked eye doctors around the U.S. if they were seeing more nearsighted kids, the answers were: ‘Absolutely.’ ‘Yes.’ ‘No question about it’.”

“In Europe as well, young adults are more likely to need glasses for distance vision than their parents or grandparents are now. Some of the lowest rates of myopia are in developing countries in Africa and South America. But where Asia was once seen as an outlier, it’s now considered a harbinger. If current trends continue, one study estimates, half of the world’s population will be myopic by 2050.”

Experts continue to argue about precise details, but there is general agreement that the condition is caused by too much time inside focusing on near objects like books, phones, videogames and such, and too little time in the sunlight scanning distant objects. 

“In humans, the majority of babies are born farsighted. Our eyes start slightly too short, and they grow in childhood to the right length, then stop. This process has been finely calibrated over millions of years of evolution. But when the environmental signals don’t match what the eye has evolved to expect—whether that’s due to too much near work, not enough outdoor time, some combination of the two, or another factor—the eye just keeps growing. This process is irreversible.”

This phenomenon is more than a curiosity.  Myopia can lead to unhealthy eyes and even blindness.

“Nearsighted eyes become prone to serious problems like glaucoma and retinal detachment in middle age, conditions that can in turn cause permanent blindness. The risks start small but rise exponentially with higher prescriptions. The younger myopia starts, the worse the outlook. In 2019, the American Academy of Ophthalmology convened a task force to recognize myopia as an urgent global-health problem. As Michael Repka, an ophthalmology professor at Johns Hopkins University and the AAO’s medical director for government affairs, told me, ‘You’re trying to head off an epidemic of blindness that’s decades down the road’.”

For those interested in more information, try a National Institutes of Health publication: Myopia: a growing global problem with sight-threatening complications. 

Since the problem has been severe for the longest in Asia, that is where research has indicated that the problem can be alleviated by specific treatments to limit the elongation of the eyeball.

“Over the past two decades, eye doctors—mostly in Asia—have discovered that special lenses and eye drops can slow the progression of nearsightedness in children.”

These treatments seem to limit myopia development but not eliminate it.  And none have been approved by the FDA for use in myopia control.  However, if the trend continues, parents will demand them.

Children are already subject to competition between parents striving to provide the best for their offspring.  It is such competition in education and recreational pursuits that contributes to this surge in myopia.  Myopia will become another arena in which the well-off will seek to separate themselves from the masses by investing in these treatments.  And the cost of raising a child will again escalate.

Or, we could just demand that our children spend more time outdoors.

 

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