How many people are short-sighted in China?
summary
According to the latest research report of the World Health Organization, there are as many as 600 million myopia patients in China. The myopia rate of high school students and college students has exceeded 70%, and that of primary school students is close to 40%. The myopia rate of teenagers in China ranks first in the world, and this data is still rising year by year.
How many people are short-sighted in China?
Why is the child easy myopic? Research shows that increasing outdoor activity time has a clear protective effect on the occurrence and development of juvenile myopia. Therefore, parents must take their children outdoors. The more outdoor activities, the less possibility of developing myopia. For children who want to prevent myopia, outdoor activities should be at least 2 hours a day, 3 hours is better.
The metabolism of sugars in sweets and carbonated drinks requires a lot of vitamin B1 and reduces the content of calcium in the body. Calcium is the "protector" of eye tissue. Lack of calcium in the body will not only cause the decrease of elasticity of the retina, the increase of pressure in the crystalline body, the elongation of the anterior and posterior diameter of the eyeball, but also cause the degeneration of cornea and ciliary muscle, Thus, the elasticity of eyeball wall is weakened and myopia is deepened.
When the noise acts on the auditory organs, it will also "affect" the visual organs through the role of the nervous system, making people's vision weakened. In short, noise can make the human eye less sensitive to light intensity. The research of relevant experts shows that when the sound intensity is above 90 dB, the sensitivity of rod cells in the fundus retina to distinguish light brightness begins to decline, and the time to recognize weak light reaction prolongs. When the sound intensity exceeds 45 dB, 40% of people's pupils dilate. When the sound intensity reaches 115 dB, the adaptability of eyes to light brightness decreases by 20%, accompanied by the weakening of color vision.
matters needing attention
If the light is too strong, it will cause strong reflection, stimulate the eyes, make the eyes uncomfortable, and it is difficult to see the font; Too weak light, insufficient written lighting, eyes can not clearly see the font, the head will be forward, close to the book, the above two situations will lead to eye fatigue, excessive adjustment or spasm and form myopia. Take care of your eyes, take care of your growth.
