After birth, infants are almost always farsighted or have hyperopic astigmatism because of the small eyeball and short eye axis. As they get older, the eye grows and the eye axis grows to develop into an orthoptic eye (no hyperopia, myopia or astigmatism). If we look at the eye as a sphere, it has three axes, namely the longitudinal axis, the transverse axis, and the sagittal axis (i.e., the ocular axis), and the three axes of a positive sphere are of equal length. In preschool children, most of the eye axes are shorter than the longitudinal and transverse axes and are oblate, which is a farsighted eye. At the age of 6-8, the eye axis gradually grows into a positive sphere with three axes of equal length, about 24mm, which is an ortho-optic eye. Optically, for every 1mm shortening of the eye axis, the hyperopia increases by 300 degrees; for every 1mm lengthening, the myopia increases by 300 degrees. Physiological hyperopia in preschool children Preschool children’s eyes have a certain amount of physiological hyperopia in their growth and development, which is a normal process of eye development. Its normal value is within 200 degrees of hyperopia at the age of 3-4, within 150 degrees of hyperopia at the age of 4-5, and within 100 degrees of hyperopia at the age of 6-8. If it exceeds the normal range, it is abnormal or pathological hyperopia. Abnormal or pathological hyperopia is a sign of poor or abnormal development of the eye, and abnormal or pathological hyperopia will further affect the normal development of the eye, putting it in a bad vicious circle. This effect is proportional to the degree of hyperopia or the difference in refractive error of both eyes, i.e. the greater the degree of hyperopia, the greater the difference in the degree of both eyes, and the greater the effect on the growth and development of the eyes. The difference in refractive error between the eyes >250 degrees is called refractive error. The main effects of abnormal or pathological hyperopia on eye development are: low vision (normal children’s vision is ≥0.6 at the age of 3-4, ≥0.8 at the age of 4-5, and ≥1.0 at the age of 5-6, below the above standard is called low vision), amblyopia (no organic lesion in the eye, but the vision cannot be corrected to 0.8 or more with glasses), strabismus and other visual dysfunction, such as fusion dysfunction (in the same vision machine examination, the two images cannot be fused together. In the same vision machine, two images cannot be fused into one, such as lions cannot be caged, animals’ ears and tails cannot grow on the body, etc.), and stereo vision disorders. Early intervention and treatment The eyes during the growth and development period have strong plasticity, and it is possible to restore abnormal or pathological hyperopia to normal development as long as it is detected early and correct medical intervention and treatment is taken in time. The main manifestation of abnormal or pathological hyperopia is low visual acuity. The most effective and easiest way to detect low visual acuity in children at an early stage is visual acuity examination. The most effective and easiest way to detect low vision in children at an early stage is through visual acuity examinations. In order to accurately measure the refractive nature and degree of refraction in children, it is important to emphasize that children must be examined by atropine dilated pupils. Experts at home and abroad have repeatedly called for children’s glasses to be examined by atropine dilated pupils because children’s eyes have a strong ability to adjust, and other methods of optometry such as original pupil optometry and double-starred rapid dilated pupil optometry are inaccurate and undesirable for children. Amblyopia, strabismus and other visual dysfunctions caused by hyperopia in children are expected to return to normal as long as they are treated and trained correctly during childhood.