1. The problem of covering the eye This is a very specific and practical problem, and is the key to the success or failure of traditional cover-up therapy. Covering the primary eye must be strict and thorough. It is common for parents of children to use a piece of black lens or use a piece of paper to stick on the primary eye lens for convenience and saving. The children will peek through the top edge of the frame or through the gap between the frame and the skin, especially on the side of the nose; some children remove their glasses when no one is around. 2. Be alert to the occurrence of masked amblyopia Follow-up examinations should be reinforced during the masking period. Each time the follow-up examination must check the visual acuity of the healthy eye and the nature of the gaze, to be alert to the occurrence of masked amblyopia. The visual acuity of the covered eye (primary eye) decreases and the point of gaze changes from a central concave to a paracentral gaze. Masked amblyopia is generally reversible, but it has been reported in the literature that unrestricted masking of one eye during infancy can cause irreversible masked amblyopia. It should be reviewed immediately. 3. Amblyopia recurrence The biggest problem of amblyopia treatment is how to consolidate the efficacy and prevent recurrence. Every patient with cured amblyopia has the possibility of relapse before the vision has matured. All cured patients should be followed up until visual maturity. Therefore, patients with amblyopia should also be observed for a 5-year cure rate, just like tumors. A 3-year follow-up of amblyopia cure should be appropriate. The main reasons for relapse are that the patient does not follow the doctor’s orders for regular follow-up; the normal vision obtained is not consolidated and the primary eye is opened on its own. In order to maintain the effectiveness of the treatment, the patient should be seen once a month during the amblyopia treatment.