Visual acuity is the most important criterion for reflecting good or bad visual function, and when a child has an eye problem, it is easier to draw parents’ attention if there is a change in appearance. Some eye diseases are not abnormal in appearance, painless, children do not understand, parents do not pay attention, and therefore often miss the best time for treatment, as parents need to constantly care about their children’s vision, in the absence of a vision chart, the following performance can help to find the child’s vision good or bad. How to detect abnormal vision in babies? ① The degree of distance and clarity of vision compared to children of the same age. ②For children who go to school, let your child try to sit in the back row of the classroom and observe whether he/she can read the words on the blackboard. ③Whether you need to lean closer to read or watch TV to see clearly. ④Whether there is any change in eye position, whether the position of both eyes is symmetrical, whether there is strabismus, etc. Generally speaking, children should learn to use the vision chart to check their vision as early as possible. Infancy is an important stage of eye development, but infants cannot actively reflect their vision, and it is difficult for others to check vision for infants, so infant vision is often neglected. However, you can carefully observe whether the infant’s vision is normal from some eye-related actions. When an infant is born with only a sense of light, the pupil can be seen to narrow immediately when a flashlight is shone on the black eye, which is called the “response to light. The presence of the “light response” means that the infant has a sense of light. At the age of one month, infants can see hands, bottles, toys, and other objects moving in front of them, but their eyes do not turn with the movement of their hands, and they can only blink when they see something, i.e., the “transient reflex”. At 3 months of age, the eyes can follow a slow-moving object and turn, i.e., the “follow movement”, when vision reaches about 0.02. The eyes can then gaze at the object for a short time, called the “fixation response”. At 6 months of age, vision can reach 0.5 or more, and at 3-6 years of age, normal vision can reach 1.0.