Refractive spherical lens values within the range of +0.50D to -0.25D are generally considered normal for the human eye and are called orthokeratology. However, children are physiologically farsighted, and the exact normal value is age-dependent. The refractive error of the human eye reflects the position of the focal point of parallel light rays in relation to the macular center of the retina under the relaxed state of eye regulation. If the focus falls exactly on the macular center, it is called orthokeratology, that is, the normal visual state of the human eye, and the refractive error value is within the range of +0.50D to -0.25D. Physiologic hyperopia exists in children, and the exact normal value is age-related. Generally, there should be about 200 degrees of physiological hyperopia at the age of 3-6 years old, and about 100 degrees at the age of 7-10 years old. Usually, physiological hyperopia disappears at about 12-14 years old, but hyperopia higher than that for the age is not normal. It is recommended that patients with refractive errors seek prompt medical attention to evaluate their condition and follow the doctor’s instructions for treatment.