At present, primary and secondary schools all over the country have resumed classes, and children have started intense offline learning. The new semester is a new starting point, but the majority of parents also start to worry about the children's excessive use of eyes, resulting in myopia or myopia deepening. Myopia is a public health problem, and the prevention and control of myopia requires multiple efforts. As early as 2018, the National Health Commission and other eight departments jointly issued the Implementation Plan for the Comprehensive Prevention and Control of Myopia in Children and Adolescents, clarifying the responsibilities of various aspects. After years of work, China has formed a model of myopia prevention and control for children and adolescents, which is "government-led, department collaboration, medical technology support, school main body, student center, family collaboration, and social cohesion". In recent years, 15 departments, including the Ministry of Education, the National Health and Health Commission, and the General Administration of Sport, have jointly promoted schools and all sectors of society in all regions to jointly implement the action to prevent and control myopia in children and adolescents. Liu Peijun, deputy director of the Department of Sports, Health and Arts of the Ministry of Education and a first-level inspector, said that through a series of measures, the prevention and control of myopia in children and adolescents has achieved phased results, and the overall goal of national prevention and control has been achieved. According to the data, the overall myopia rate of children and adolescents nationwide in 2018 was 53.6%, decreased to 50.2% by 2019, and decreased by 0.9 percentage points in 2020 compared with 2018. Since the COVID-19, students have spent more time online at home and using electronic screens, and the incidence of myopia has rebounded. There is a long way to go in the prevention and control of myopia. In the new semester, the knowledge of eye care should become an important lesson. Li Li, chief ophthalmologist of the National Children's Medical Center and Beijing Children's Hospital, carried out science popularization. What behaviors should children be alert to myopia? Look at things very close, for example, when watching TV, reading or using electronic products, the eyes are very close, and when doing homework, stoop and bow; He likes to squint, frown, tilt his head, look up, often pull the corners of his eyes, rub his eyes, and blink frequently; When writing homework, they may not write neatly, or become irritable, or even tired of learning. If the child has the above signals, he may have myopia. It is recommended that parents take the child to a regular hospital or optometry institution for eye examination, mainly including vision, fundus, eye axis, diopter, etc., to exclude organic eye diseases and pseudomyopia. Once the child is diagnosed as true myopia, he/she should actively cooperate with ophthalmologists to correct it, and also do a good job in myopia prevention and control to prevent myopia from deepening. How should children be prevented from myopia? Ensure 2 hours of outdoor activities every day. The most effective way to prevent myopia is outdoor activities. Outdoor activities in the sun can effectively increase the content of dopamine in the eyes, increase the thickness of choroid, inhibit the growth of eye axis, and control the development of myopia. Therefore, it is best to exercise outdoors when the sun is full. Control the time and distance of eye use. On the basis of ensuring 2 hours of outdoor activities every day, children aged 3-6 should not use electronic products for more than 1 hour every day and not more than 15 minutes each time. If you want to watch cartoons, you'd better use a TV, projector, etc. to ensure the appropriate screen distance. The mobile phone screen is small, try not to touch. When using the projector, pay attention to the screen resolution. Effective contrast sensitivity can make children see more clearly and reduce fatigue. Create a good reading environment, not