Will children become myopic if they face electronic screens for a long time?

Author: Tang Qin, Researcher of Chinese Medical Association

Reviewer: Qiu Weiqiang, Chief Physician, Peking University Third Hospital

In modern society, while various electronic products bring convenience to people's lives and work, they also pose a great test to eyesight, especially for children in their developmental stage. What parents worry most is whether long-term exposure to electronic screens will cause their children's myopia.

Figure 1 Copyright image, no permission to reprint

1. Why do eyes become myopic?

Myopia is an eye disease in which one cannot see distant objects clearly but can see nearby objects clearly. It is common in clinical practice and is more common in adolescents.

Under normal circumstances, the eyes can see things clearly near or far because of the automatic focusing function, and the key role is played by the ciliary muscle with adjustment ability. When the eyes look at objects nearby, the ciliary muscle will contract to make the "convex lens" (lens) convex and thicker, improve the ability to refract light, so that the focus will not fall behind the retina, but just on the retina; when the eyes look at distant objects, the ciliary muscle will relax, making the lens flat, so that the focus will fall just on the retina, not in front of the retina.

In this process, the ciliary muscle is like a spring, automatically contracting or relaxing according to the distance of the object. However, when the ciliary muscle is in a highly tense and continuously contracted state due to excessive use of the eyes, its elasticity will be affected, making it difficult to relax even when looking at distant objects. Over time, the eyes may become blurry when looking at distant objects. At this time, it is necessary to go to a specialist hospital for examination in time to rule out the possibility of pseudomyopia.

The factors that affect the occurrence of myopia are genetic and environmental.

1. Genetic factors

The genetic risks of different types of myopia are different: simple myopia is generally caused by acquired factors, and the genetic risk of this type of myopia is very small, while the genetic risk of pathological myopia is relatively large.

Without intervention, the incidence of myopia in children whose one parent is myopic is about 24%; but when both parents are highly myopic, the incidence of myopia in children will increase significantly, reaching about 90%.

Figure 2 Copyright image, no permission to reprint

2. Environmental factors

Close, prolonged, and uninterrupted use of the eyes is the main cause of myopia. Therefore, regardless of whether the parents are myopic or not, if the children spend too much time reading and studying and too little outdoor activities, they are likely to develop myopia.

Most children and adolescents who have been diagnosed with myopia have axial myopia, which means that the length of the eye axis has increased compared to normal. The more it increases, the greater the degree of myopia will be, and it is irreversible. Therefore, once axial myopia caused by eye axis growth occurs, it cannot be cured, but through some prevention and control measures, the growth of myopia or eye axis length can be delayed, reducing the possibility of developing high myopia.

2. Do electronic screens affect myopia?

From the perspective of the causes of myopia, it is not the electronic screen itself that causes damage to the eyes, but the long time spent in front of it each time. If you have the habit of using your eyes at close range without control and without interruption, you may develop myopia even if you do not touch the electronic screen at all. Therefore, if you want to protect your eyesight, you should still look far away to give your eyes a full rest.

At the age of 3 to 5, it is recommended that children watch TV for no more than 1 hour a day and take a break every 15 minutes. At the same time, parents should not let their children think that they can watch TV every day. They must help their children choose programs and it is best to watch with their children. In addition, it is best for children of this age not to play with electronic products, and try to read less books or write and draw less.

Primary school students can play with electronic products, but the time needs to be controlled. It is best not to exceed 15 minutes each time, and no more than 1 hour in total per day. When using electronic products to study, they should take a break and relax for 10 minutes after half an hour.

In addition to necessary studies, young people should consciously reduce the time they use electronic products outside of study, and take timely breaks while using electronic products to avoid eyes fatigue.

In addition, try not to let your children use electronic products before going to bed, because the blue light from electronic screens may affect the human body's sleep structure, thereby reducing sleep quality. At the same time, receiving too much information before going to bed will also interfere with sleep, and lack of sleep will also affect eye health.

3. How to protect your eyes

Since myopia is irreversible, parents should protect their children's eyes to prevent the occurrence or continued worsening of myopia. Measures include:

1. Avoid reading or studying for long periods of time

When children are reading or studying, they should pay attention to the combination of work and rest in their eyes. It is best to rest for 5 to 10 minutes after every 30 to 40 minutes of using their eyes, and look into the distance to relax their eyes or close their eyes to rest.

Figure 3 Copyright image, no permission to reprint

2. Develop good eye habits

For example, maintain a correct sitting posture, sit upright when reading or writing, do not read in direct sunlight, in a shaking car, or while lying or prone with your head tilted, and use your mobile phone or computer in a well-lit environment. In addition, you must persist in and use the correct technique to do eye exercises, and pay attention to the cleanliness of your hands during the process to avoid further damage to your eyes due to bad eye habits.

3. Maintain eye hygiene

Do not rub your eyes, especially without washing your hands.

4. Ensure nutrition and a good work and rest schedule

Adequate nutrition and sleep are the "magic weapons" to ensure eye health.

5. Ensure sufficient activity time

Try to do activities outdoors as much as possible, so as to prevent myopia. The time for outdoor activities should also be sufficient, accumulating 2 hours a day or 20 hours a week; if the time cannot meet the above requirements, you should increase the time for outdoor activities as much as possible, which is also helpful in preventing myopia.

In summary, long-term exposure to electronic screens will not necessarily cause children to become myopic, but long-term exposure to electronic screens will increase the risk of myopia. Therefore, parents should encourage and support their children to effectively implement the above eye protection measures and develop the habit of using electronic products in moderation.

References

【1】Chen Qingfeng, Wang Xinmei. Parents have foresight, and children will not be myopic[M]. Beijing: People's Medical Publishing House, 2019.

【2】Wang Ningli, Li Shiming. Handbook for the prevention and control of myopia among high school students[M]. Beijing: People's Medical Publishing House, 2021.

[3] Ma Jun, Xu Zhongqing. Good eyes make the world bright: a book about eye care for children[M]. Tianjin: Tianjin Science and Technology Press, 2020.