Adolescents between 6 and 18 years old, whose organs are growing and developing, are extremely prone to eye strain, pseudomyopia and development of positive myopia due to heavy study, poor nutrition, neglect of eye hygiene and treatment, etc. Therefore, ophthalmologists call it the eye susceptibility period. The susceptible period is the high incidence of pseudomyopia and myopia in adolescents. The eye structure of this group of teenagers is relatively young and easily deformed, and the eye axis is easily elongated. In addition, they usually do not pay attention to eye hygiene and have a weak awareness of eye care, so they can easily form pseudomyopia, and if they are not treated in time at the initial stage, then it will soon develop into true myopia. Pseudomyopia is the early stage of myopia, which is a reversible change in myopia, and if treated in time, vision can be restored. Pseudomyopia is easily ignored by students and parents who are not aware of its potential harm, and it is usually too late to recover after 3-6 months when pseudomyopia develops into true myopia. Therefore, treating pseudomyopia is a critical period to stop the deepening of myopia in teenagers. Therefore, as parents and teachers of children, they should pay attention to observe their children more from their daily life and study, detect it as early as possible, check their vision in time, and take preventive and curative measures quickly so that they can safely pass the myopia susceptibility period.