The decrease in exposure to outside light seems to be an important factor in this increase.
Take a look and you will see: the myopia generation is growing in front of your eyes. A largely unrecognized epidemic of myopia affects children’s eyes.
People with myopia can clearly see nearby objects, such as text on paper, but their long-distance vision is very blurred. They may need to wear glasses or contact lenses for correction to see the blackboard clearly, riding a bicycle, Driving or recognizing faces on human faces. street.
The increase in myopia rate is related to changes in children’s behavior, especially when they spend little time outdoors, and how often they watch screens indoors instead of enjoying bright activities throughout the day. Gone are the days when most children played outside between school time and dinner time, and the devastating pandemic last year may have made the situation worse.
The tendency of myopia is determined by heredity and environment. Children with one or two myopic parents are more susceptible to this disease. However, although genetic modification takes many centuries, the prevalence of myopia in the United States has risen from 25% in the early 1970s to nearly 42% just three decades later. The increase in myopia is not limited to highly developed countries. The World Health Organization estimates that by 2050, half of the world’s population may be nearsighted.
Because the speed of genetic changes is not fast, experts believe that environmental factors are likely to lead to an increase in myopia, especially for children to reduce exposure to light. For example, consider the factors that keep modern children indoors: the emphasis on academic research and the resulting tasks, the irresistible attraction of electronic devices, and safety issues that require the supervision of children and adults in outdoor games. All these factors greatly limit the time that children now spend outdoors during the day, which impairs the clarity of their long-distance vision.
Recent research suggests that months of imprisonment by Covid may accelerate the silent development of myopia in young children. A Canadian study conducted a study on children’s physical exercise, outdoor activity time, screen time, and social media usage during the coronavirus lockdown in early 2020. The results showed that eight-year-old children spend more than five years in front of a screen dedicated to entertainment every day. Hours, in addition to the screen time required for homework.
The report and a new study of Chinese school-age children after five months of imprisonment for Covid-19 inspired the title of an article titled “The Year of Quarantine Myopia in 2020” in JAMA Ophthalmology on January 14. Researchers from Emory University in Atlanta, the University of Michigan in Ann Arbor and the Eye Hospital of Tianjin Medical University in China said that the eyesight of 123,535 elementary school students after school from January to June last year had dropped significantly.
Compared with the results of the previous annual review, the ability to see distant objects has been significantly reduced, especially among children aged 6 to 8. Based on the changes in vision measured at the beginning of the school year from 2015 to 2019, children’s nearsightedness became much more than expected, but in older children, vision did not drop as sharply.
“Given that younger children are assigned fewer online learning tasks than older children, the rapid progress of myopia in younger children is unlikely to be caused by longer screen time or homework. This requires myopia, For example, reading, typing, doing homework or the JAMA Ophthalmology Research Group wrote that they play video games. The most likely explanation is that they are not exposed to outside light.
As the editor of the Erasmus University Medical Center in the Netherlands suggested, “young children may be more sensitive to myopia triggers from the environment.” An earlier ophthalmology study conducted among children in Sydney also showed that only The youngest child with myopia spends more time on tasks that require close observation instead of during the day.
Although many people have long believed that excessive reading can promote myopia in children, the current thinking is that spending too much time indoors will have greater consequences, and may better explain close work or screening time and myopia Any associations that may exist between.
Neil M. Bressler, an ophthalmologist at the Johns Hopkins University Medical Affiliated Institution, said that high-intensity external light can have a major impact on the shape of the eye, which in turn affects the ability to see images clearly.
In order to focus, the light in the image must converge on the retina. In myopia, convergence occurs in front of the retina, and a corrective lens is needed to redirect the incident light in order to focus distant objects.
Most children are slightly farsighted at birth. Their eyes are shaped like partially reduced balloons, causing the image to converge behind the retina, but as they grow, their eyes will stretch into a sphere, causing the image to converge directly on the retina. However, if the extension does not stop at a certain point, the eye will become more elliptical and the image will converge in front of the retina, which is the definition of myopia. According to Bresler, outside light stimulates the release of dopamine, which slows down the elongation of the eyes.
Although myopia is on the rise globally, the epidemic is still spreading in East Asia and Southeast Asia, where 80% to 90% of high school students have myopia.
The growing concern for the prevalence of myopia has gone beyond the need to wear glasses, contact lenses, or, for those who want and can afford it, laser treatment by changing the shape of the cornea to change the direction of the image. Generally, patients with myopia are more likely to have vision-threatening complications in later life, such as cataracts, glaucoma, and macular degeneration in the center of the retina.
Bressler pointed out that if the situation becomes extreme, “it may be difficult to correct.” He explained that the eyes will stretch, the retina will stretch and scar tissue will form, and the gel in the center of the eye will stick to the sides of the eye, causing the retina to tear or detach. .
These risks have prompted research into treatments that can prevent myopia from becoming a pathology. One of the methods being studied is to use multifocal contact lenses with high magnification to slow down the development of myopia in children.
Another method that is currently considered more promising is to use atropine drops to minimize excessive eye elongation. The third strategy is called Orthokeratology, which involves wearing contact lenses at night to change the shape of the cornea, making the edges of the eye more farsighted, and possibly slowing down the elongation of the eye.
Bresler said: “The pandemic has intensified the fire, but we still have not been treated.” Today, the most effective preventive measure may be that young children spend less time in front of the screen and more time outdoors.
People with myopia can clearly see nearby objects, such as text on paper, but their long-distance vision is very blurred. They may need to wear glasses or contact lenses for correction to see the blackboard clearly, riding a bicycle, Driving or recognizing faces on human faces.street
Factors that keep children at home
• Academic research and the resulting tasks
• Attraction of electronic equipment
Safety issues that require adult supervision in outdoor activities
• All these factors greatly limit the time that children now spend outdoors, thereby impairing their long-distance vision
• The World Health Organization estimates that by 2050, half of the world’s population may be nearsighted
• The epidemic has caused severe damage in East and Southeast Asia, where 80% to 90% of middle school students already suffer from myopia
• One of the methods under study is to use multifocal contact lenses with high magnification to slow down the development of myopia in children
•Using atropine drops can minimize excessive eye elongation
• The third strategy is called Orthokeratology. Wear contact lenses at night to change the shape of the cornea, making the edge of the eye more farsighted and possibly slowing down the elongation of the eye.