I. Hazards 1. Developmental Myopia in children before the age of 7 (preschool) is usually lifelong developmental, and the younger the age, the higher the degree of myopia in the future. If myopia in children is not well controlled, more than 95% of them will develop into high myopia of 600-1000 degrees or more as adults. The higher the degree of myopia in children, the greater the chance of blindness due to fundus hemorrhage and retinal detachment. When myopia in children becomes high, about 1/4 of them may suffer from complications such as macular hemorrhage or retinal detachment, resulting in low vision and even blindness. Myopia in children is difficult to control with traditional myopia treatment methods. (1) Children’s growth and development are at their peak, which makes their eyes grow longer easily. (2) Because of poor compliance and the opportunity to “look close”, it is particularly difficult to control the distance and duration of children’s near vision. (3) The traditional myopia treatment device can neither shift the focus of near to offset the main cause of myopia “near”, nor can it block the two key aspects of myopia by offsetting the near reflection and improving the focus sensitivity, so the effect is almost 100% bad. 4, can cause refractory amblyopia and refractory amblyopia due to low visual acuity, resulting in form deprivation, can in turn cause aggravation of myopia. Almost 100% of children with medium and high myopia have amblyopia. Myopic amblyopia in children is poorly treated with ordinary amblyopia apparatus, while the use of high-precision amblyopia apparatus can improve the efficacy, but because amblyopia apparatus treatment is a kind of super close work, ordinary amblyopia apparatus can cause and aggravate myopia. The main cause of myopia is the use of defocused or defocused telephoto lenses to offset the “nearness”. The defocusing lens is the third generation of static teleoptics, while the automatic (shift-focus) teleoptics is the fourth generation, dynamic and enhanced teleoptics. Automatic telecine is the strongest telecine at present. Myopic terminal control method can be used, that is, at the end of each day, when reading at night before going to bed, can automatically produce 300-500 degrees of hyperopia (i.e., front defocus refraction), thus offsetting the accumulation of myopia caused by reading, writing, reading computers, etc. during the day, and induce the shortening of the eye axis, usually each shortening of 1mm is equivalent to slowing down the occurrence and development of myopia by 300 degrees, with an efficiency of 85%. 2.Use eye sensitivity (focusing) distant lens (can improve eye focusing sensitivity and expand the field of vision) to block the first key link of myopia in the pooled field of vision reduction and the second key link of “focusing sensitivity decline”. (2) Cure amblyopia as early as possible because amblyopia can cause form deprivation myopia, which can aggravate myopia. (3) If you have astigmatism, you should correct the astigmatism by 25~50 degrees. Because astigmatism undercorrection and miscorrection, can increase the eye focusing burden. And cause, aggravate myopia. Avoid strenuous sports: If children are highly myopic, avoid high diving and blue ball and other strenuous sports to prevent fundus hemorrhage and retinal detachment. Annual fundus photography: Children with high myopia must take a fundus photo and have an ultrasound examination of the eye axis once a year. To understand the corresponding changes, whether there are complications, so that the color can be targeted treatment.