The recommended lower limit of normal visual acuity for children of different ages is 0.5 for children aged 3 to 4 years, 0.6 for children aged 4 to 5 years, 0.7 for children aged 6 to 7 years, and 0.8 for children aged 7 years or older. Therefore, if a child’s visual acuity is above the low value for the corresponding age group, for example, a child aged 3 years has 0.5 or more visual acuity, and the difference in visual acuity between the two eyes is less than two lines, and there are no risk factors in the eye that cause amblyopia Factors, such as strabismus, ptosis and cataracts, are not immediately diagnosed as amblyopia, and can be observed regularly. The normal adult eye axis length is 22-24mm; generally the baby’s eye axis is about 16mm at birth and grows to 20mm at age 3. If the child has +200 degrees at age 3, +150 degrees at age 8, and +100 degrees of hyperopia at age 12, then the child is not prone to myopia in adulthood. At the age of 4, although farsighted, but the degree of farsightedness ≤ 150 degrees, 6 years old farsightedness ≤ 100 degrees, the future may develop into myopia. Experts reminded that during the summer holidays, children should watch television, the Internet should be restrained, about half an hour to rest the eyes, do more outdoor sports (playing table tennis or badminton especially helps to exercise the extraocular muscles, relieve eye fatigue), avoid excessive eye use; do eye exercises before going to bed is particularly conducive to improving eye nutrition. In addition, children aged 3 to 6, 10 to 13 and 16 to 18 years old have rapidly developing eyes and bodies, so they should pay attention to balanced nutrition, eat less sweets and fast food, and eat more vegetables and fruits at this stage.