We live in a veritable epidemic of myopia

A group of colleagues with glasses in the office (Photo: Getty)

In 2015, the journal Nature published a disturbing article with a simple but straightforward title: Myopia boom, a vision problem that was spreading rapidly around the world and at that time had already earned the title of a global myopia epidemic. The statistics presented that year were already astonishing, especially among the youth. In Europe and the United States, myopia already affects 50% of people under 19 years of age, while in some Asian countries such as Taiwan, Singapore or China, this percentage increases with displeasure. Sixty years ago, 10% to 20% of the Chinese population was myopic, and today that number has increased to 90% among adolescents and young adults. But the world record is found in Seoul, the capital of South Korea, where up to 96.5% of 19-year-old males suffer from nearsightedness.

Half of young people in Europe and America suffer from myopia, while in many Asian countries such as China or Taiwan this percentage reaches 90% | Nature

Almost ten years have passed since it was published in Nature and the journal The numbers are even higher.. A few days ago, the popular Wired offered a review on the subject.The world is going blind” with a clear warning: “If this continues, by 2050 Half of the world’s populationYou may need glasses, contact lenses, or even surgery.

The Myopia This is a refractive error in our vision Difficulty focusing properly on distant objects Appears blurry and with little definition. Although there are diseases that can trigger it, its origin is mostly genetic, passed from parents to children. However, in recent years, many Scientific studies It has been shown that there are predisposing factors beyond genes. The amount of time we spend outdoors and hours of natural light are decisive factors influencing this myopia epidemic.

Number of cases (in millions) and expected impact by 2050 | Holden et al (2016)

Close connection between natural light and myopia

A A study carried out in 1990 Adolescents who attended schools known as “in Israel” were identifiedYeshivas” They spent hours reading religious texts Very high rate of myopia Students in other schools spend more time outdoors and fewer hours in classrooms than students in other schools. Today we know that dopamine, a neurotransmitter, is important in countless functions of the nervous system. In this regard, it is essential An exploratory study At the Ophthalmic Research Institute at the University of Thuringia in Germany, newborn chicks are exposed to different levels of light for 15 minutes daily. After a few days, chickens exposed to natural light had 40% less myopia than the group exposed to artificial light.

But globally, there was one moment when the lack of natural light and increased myopia became apparent: confinement during the COVID-19 pandemic. Last year, the Department of Ophthalmology at the University of Hong Kong published a comprehensive analysis Increase in myopia and lifestyle changes among school children during epidemics. Time devoted to outdoor activities decreased (from 1.27 h/day to 0.90 h/day), while time in front of a screen increased from 2.45 h/day to 6.89 h/day, which, according to the authors, “increases the likelihood of myopia” while issuing a clear warning. : “Our results help alert vision professionals and policy makers, educators and parents, that they need to make concerted efforts to prevent childhood myopia.”

What do the experts say?

We are in touch Conchi Lillo, PhD in Neuroscience from the University of Salamanca and researcher in the Neuroscience of Vision at the Neuroscience Institute of Castilla y León. “We assume that the development of myopia (especially in children) is directly related to the excessive use of screens (now, had a direct connection between this close visual effort and the increase. As is well known, correlation does not always imply causation,” explains the neuroscientist.

“What we now know is that screens and books are not the direct cause of this increase, but by keeping children away from natural (sunlight) light, their accessory. Development of eye growth (the myopic eye is longer than normal), by promoting the secretion of Dopamine Certain retinal cells appear to inhibit this abnormal development of the eye (although the underlying molecular mechanism of this phenomenon is still unknown). Experiments with experimental animals and humans confirm this. Filters are of no help, and in fact the best suggestion to reduce these symptoms is to blink more often and take regular breaks. The 20/20/20 rule. That is, take a 20-second break every 20 minutes to look at an object 20 feet (6 meters) away (and try to focus). “If it’s through a window and with sunlight, the better,” says Lillo.

A case in point is the Taiwan issue

Pei-Chang Wu, an eye surgeon with decades of experience at Kaohsiung Memorial Hospital in southern Taiwan, writes in The Wired article. When Wu began his surgical career in the late 1990s, most of his patients were in their sixties and seventies. But in the mid-2000s, he began to notice a worrying change. The people on his operating table were getting younger. During those years, the rate of myopia among 15-year-old Taiwanese youth increased to 74% and continues to rise until it reaches 90% today.

Recognizing the serious problem they faced, Taiwanese authorities launched a national program called Tian-Tian 120. It urges children to spend at least 120 minutes outside each day. The results were immediate and impressive. After an increasing trend for several years, the prevalence of myopia among Taiwanese primary school children peaked at 50 percent in 2011 and then began to decline. In a few years, it was 46.1 percent… but then Covid hit and “an entire generation of kids was stuck indoors at once. In China, Turkey, Hong Kong and India, studies have shown that myopia worsened during the Covid lockdowns. Taiwan is no exception.

Still, we already know the way to go. Get out of our screens and televisions, our dark video game rooms, our closed offices with fluorescent lights on the ceiling…get outside and look, focus and return to the light.

Also in the video: Cuban boy regains sight with experimental treatment at Florida hospital