Newborn babies, all parts of the eye tissue and function are immature, can only see about an adult man a tie long distance, about 18cm, at this time belongs to the farsighted; 3 months, the infant’s visual acuity is about 0.01-0.02, can follow the moving small objects, but also can identify different colors; 5-6 months infant visual acuity is about 0.04-0.08; 7-8 months, the infant can look in the same direction for a long time; at 1 week of age, visual acuity is about 0.2-0.3, and vision is basically close to that of adults; at 3 weeks of age, visual acuity is about 0.6, and there is fine visual reflex movement at this time; at 5-6 weeks of age, visual acuity can approach or reach 1.0 or even above, and vision tends to be perfect at this time. In addition, the examination of visual acuity can choose different methods according to the age, for example, for babies within 18 months, you can choose to use the strip vision chart; for babies between 18 months and 3 weeks, you can choose to use the dot vision disc; for babies after 3 weeks, you can choose to use the standard vision chart for examination. Usually, vision checkups need to be done once every 3-6 months so that you can keep track of your child’s vision. If your baby’s vision lags behind normal children’s vision, you need to take your child to a regular eye hospital for a checkup. The most critical period of eye development is before 3 weeks and the sensitive period is before 9 years old, during which time the eyes should be protected and problems should be treated promptly.