Passive visual rehabilitation of amblyopia includes covering or suppressing healthy eyes. These two visual rehabilitation methods will force the patient to use amblyopia, and stimulate visual improvement by reactivating the visual pathway.

Covering non amblyopic eyes is called direct covering, and covering amblyopic eyes is called indirect covering or reverse covering. The covering can be complete or partial according to the covered field of vision. Complete covering means that the whole field of vision is blocked, while partial covering means that only part of the vision is covered. Each covering has its own clinical advantages and disadvantages.

Amblyopia visual rehabilitation with covering method is applicable to strabismus amblyopia, anisometropia amblyopia or other types of monocular amblyopia. Because the vision of both eyes of patients with binocular ametropic amblyopia is similar, most of them do not need to be covered. If the difference between the vision of both eyes is more than two lines during the visual rehabilitation of amblyopia, they can be covered. When the vision of both eyes is close, stop covering or reduce the covering time to keep the vision of both eyes improved synchronously.