The standard visual acuity of a four-year-old child should be between 0.5 and 0.6, which is the normal visual acuity range, and if the four-year-old child is examined, there should be 100-150 degrees of hyperopia, which is a physiological degree of hyperopia, which is the normal refractive state of a four-year-old child. If the child’s visual acuity is found to be lower than normal, for example, below 0.4 after the vision test, it means that there may be some eye disease, such as refractive error or amblyopia, which needs to be actively examined. If it is refractive error, glasses can be chosen to improve vision; if it is amblyopia, active amblyopia treatment and training, including masking therapy, is the most classical method used for amblyopia treatment. This disease must be taken seriously, and if the condition is detected and actively treated before the age of four, it is still possible to return to normal.