Parents must be alert to the harm caused by myopia to children!

Abstract: myopia is not only inconvenient to life. Framed glasses, contact lenses and surgery can change this state, but they can’t solve the essential defect: the elongation of the anterior and posterior axis of the eye, which means that the focus of distant light falls in front of the retina rather than just above the retina after refraction of the lens.

myopia is almost rampant, and there are different opinions on the causes and protection behind it. This is the latest special report on the causes and protection of myopia by nature, one of the most important international scientific and technological journals. I hope it can give you inspiration and help. The severe situation of

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: the myopia problem perplexing this era

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1. The myopia of Chinese teenagers has reached 90%

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. Guangzhou, a city in southern China, has always had the largest ophthalmic hospital in China. However, about five years ago, the Zhongshan Eye Center faced an obvious need for expansion.

“thousands of children flock to the hospital every day. You can hardly walk around the hall because there are children everywhere,” said ophthalmologist Nathan Congdon.

the myopia rate in East Asia has increased unprecedentedly. 60 years ago, 10% – 20% of Chinese people suffered from myopia; Today, nearly 90% of teenagers are short-sighted. In Seoul, 96.5% of 19-year-old boys are myopic.

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data from other countries and regions also show a sharp growth. Nearly half of the population in the United States and Europe also suffer from myopia, twice that of the last century. It is estimated that by the end of this decade, the number of people with myopia will account for one third of the world population, that is, 2.5 billion. “We are entering an era of myopia,” padmaja sankaridurg said. He is the director of the myopia program at the Horton Institute of vision in Australia.

2. The harm of myopia: not only the inconvenience of life,

myopia, but also the inconvenience to life. Framed glasses, contact lenses and surgery can change this state, but they can’t solve the essential defect: the elongation of the anterior and posterior axis of the eye, which means that the focus of distant light falls in front of the retina rather than just above the retina after refraction of the lens. In severe cases, the eye axis in the degenerative area will elongate and the retina will be thinned, which greatly increases the risk of retinal detachment, cataract, glaucoma and even blindness.

myopia is gradually formed among school-age children and adolescents due to the continuous development of eyes in childhood. About a fifth of East Asians in the college age group suffer from this extreme form of myopia, and about half of them will form irreversible visual decline.

preventing myopia: exposure to sunlight, exposure to outdoor

1. Exposure to sunlight: the protective effect of sunlight on vision

some researchers believe that the data demonstrating the relationship between vision and sunlight are slightly weak. Many epidemiological studies make statistics on children’s outdoor time through questionnaire survey. However, Ian flitcroft, an ophthalmologist at Dublin children’s Hospital, questioned whether sunlight is the main protective factor for outdoor exposure. He believes that often looking out into the distance can also affect the development of myopia. “Sunshine is not the only relevant factor. Taking it as a full explanation is an overly simple summary of a complex process.”

retinal dopamine is usually produced by the circadian cycle – secreted in large quantities during the day – which directs the eye from night vision to day vision. Researchers now suspect that in a dark environment (indoor light), this cycle is broken, so the eyeball continues to develop. “If our body system can’t get enough circadian rhythm, our function will get out of control,” Ashby of the University of Canberra said. “The body system starts to fidget, indicating that it is developing in an abnormal direction.”

based on epidemiological research, Ian Morgan, a myopia research expert at the Australian National University, believes that children should stay in 1000 lux of light for three hours a day to prevent myopia. Such a light value is about equal to the light value a person will receive when wearing sunglasses and standing in the shade of a tree in a sunny summer. The illumination value on cloudy days is less than 1000 lux, while the illumination value of a lighted office or classroom is usually less than 500 lux. Morgan’s Australia has set it as a standard for children to receive 3 hours or more outdoor sunshine every day. Only 30% of 17-year-old children here are short-sighted. But in other countries and regions, including the United States, Europe and Asia, children’s outdoor time is only 1 to 2 hours.

2. Being outdoors: it can not only prevent myopia

in 2009, Morgan began to test whether the increase of outdoor time can protect the eyesight of Chinese children. He and his team at Zhongshan Eye Center conducted a three-year experiment. Among the six randomly selected schools in Guangzhou, they have added an outdoor class for children aged 6 to 7. The rest of the schools are taken as the reference object, and the curriculum will not be changed. Among the more than 900 children who participated in outdoor classes, 30% of the children formed myopia at the age of 9 or 10, while 40% of the children in the reference school formed myopia. The study is being prepared for publication.

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are more effective in a school in southern Taiwan. During all breaks, students are asked to go out of the classroom. A year later, doctors diagnosed 8% of the students with myopia, while 18% of the neighboring schools that did not force students out of the classroom were myopic.

Morgan is encouraged by these preliminary research results, but he thinks he can do better. “We have seen that the increase in outdoor time does have some effect. The question is how can we make this work more effective in practice?” He realized that many schools could not flexibly increase outdoor time. So last year, in cooperation with Congdon, he began to experiment with the idea of building a glass classroom, so that more natural light can shine in. Congdon believes that the idea of glass classroom is feasible in China.

children in some areas can’t enjoy enough outdoor sunshine because the sunshine time is too little, the sunlight is too strong when there is sun, or it is extremely cold when it is cold.

however, eye drops and light boxes are less attractive than letting children play outdoors.In addition to being good for the eyes, outdoor activities have more benefits. “Outdoor activities will also increase physical exercise, reduce obesity and improve mood pleasure. I think it’s only beneficial and free,” Rose said