As we all know, the prevalence of myopia among young students in China is quite high, and the causes are both internal and external: The internal causes refer to the physiological characteristics of young eyes, as primary and secondary school students are in a period of growth and development. The younger the eye is, the more elastic the lens is, the greater the adjusting power, and the closer its near point is. Generally, adolescents aged 10-20 years old can see the small print at 7-10 cm in front of their eyes, so they have a high degree of adaptability to close operation. When reading a book, they can’t help but bring their head closer to the book or writing, and gradually become accustomed to it. However, this requires a high degree of regulation of the eyes. This causes the ciliary muscle to spasm, and when looking at a distance, the muscle cannot relax properly, resulting in regulatory myopia (or pseudomyopia). At the same time, the extraocular muscles are also under tension and the scleral tissues are under the long-term mechanical pressure of the extraocular muscles, which gradually extends the wall of the eye, thus gradually elongating the eye axis and forming true myopia. The so-called external causes are excessive use of the eyes, and the phenomenon of “two long and one short” and “two more and one less” is common among domestic students. The so-called “two long and one short” refers to the long hours of study, long hours of continuous eye use and short hours of sleep. The “two more and one less” refers to more extracurricular homework, more exams and less physical activities. The heavy academic burden, coupled with the fact that many students do not pay attention to eye hygiene, makes the visual burden too heavy, which is one of the important reasons for the high prevalence of myopia among students.