Infancy should be the fastest developing period of the eye, 3-year-old baby vision is generally up to 0.6. Children’s visual function is in the growth process of continuous development and improvement, newborns have light perception, in the light stimulation can appear under the closed-eye action, quiet state can briefly see the object within 15 ~ 20cm, 4 ~ 8 weeks with protective transient reflexes, 2 ~ 3 months have the ability to gaze, 4 ~ 5 months can identify the shape of the object, the color, 8 ~ 9 months to see the small items, 1.5 years old can distinguish between a variety of shapes. Visual acuity at 2 years old can reach 0.5, can distinguish between vertical and horizontal lines, 3 years old visual acuity of up to 0.6, 5 years old can distinguish between various colors, 6 years old depth of vision has been fully developed, visual acuity is basically up to 0.8 ~ 1.0. If your baby’s visual acuity is significantly behind that of children of the same age, you need to find out the cause of the disease and actively seek treatment in hospital.