The determination of visual acuity can be limited by age, and in the process of health care vision screening, the international standard visual acuity chart (E chart) is used for children over 3 years of age, because after this age, most children can identify the direction and can describe what the eyes see, and the test results are more reliable. under 3 years of age, it is usually difficult to reflect objective infant and child vision, and formal eye examinations are usually not necessary to visual acuity Screening is the main focus, and children 2 to 3 years old use a child’s animal vision chart, and at a younger age, the child’s visual response is usually observed with a red ball, etc. In the case of premature and immature low birth weight children, screening for retinopathy should be performed, and is especially important for infants who have been on oxygen for a prolonged period of time after birth. Early detection of this condition can lead to successful treatment. Premature infants are at high risk for astigmatism, myopia, and strabismus, so it is important to receive regular specialty examinations. The development of the child’s vision through observation is roughly as follows: Age Vision 2 months 0.01 or so 2 years 0.3 3 years 0.6 4 to 5 years 0.8 to 1.0 The farthest length of a full-term baby’s range of vision is 20 to 38 cm, roughly the distance from the baby’s eyes to the mother’s eyes while nursing. By March, he will be able to see your face and objects close by and track moving objects. By April, your baby can spot different objects that are approaching him and he will reach for them, and by June, your baby will be able to recognize the differences between different objects. Myopia is usually the result of a larger-than-average eye length and is rarely caused by changes in the shape of the cornea and lens. It is usually noticed around age 2, when children cannot see distant objects or gaze very close to them. Correction of myopia requires glasses. The baby grows very fast and so does the eye, so he needs to be re-examined every 6 months to confirm the refractive error. Myopia usually increases rapidly over a few years and enters a stable phase after puberty. For most children, they are born farsighted and as they grow, their eyes gradually grow longer and their farsightedness decreases. Correction is usually not needed unless it exceeds the normal physiological range. Observation of the child’s state in life and play is the way to confirm the presence or absence of defects in vision. For older children, vision screening or monitoring can be done at the hospital to detect defects in vision development and correct them early.