Another question often asked by parents in amblyopia treatment is: Why do we need to re-visit regularly and change glasses often? And what is the reason why adults can wear one pair of prescription glasses for many years? This is because children’s eyes are developing, making the eye axis grow. Rough calculation, the eye axis for each 1 mm growth, glasses for farsightedness to about 3.0D less. Children are born with an eye axis length of 14.5~17.0 mm, which is highly hyperopic, and generally do not approach the adult level until they are 6~8 years old, reaching 24 mm. Therefore, the refractive error is constantly changing until the age of 6 to 8 years old, so children with amblyopia need to be re-opened regularly and change the glasses they wear. In addition, the pupil distance is constantly getting larger. If the glasses are not changed in time, both eyes will not be able to look right at the optical center of the lenses, and a trigeminal effect will occur. Therefore, it is necessary not only to re-optometry, but also to re-measure the pupil distance and re-fit the glasses. The time of re-opening and prescription is usually half a year or a year, and should not exceed more than a year. After refitting, the vision improves, the eye position becomes more normal, and changing glasses is beneficial to improve the amblyopia treatment and shorten the course of treatment.