A condition in which there is loss of vision for no apparent reason; the eye appears healthy, but vision is poor. This is commonly referred to as "lazy eye". The decreased vision is not correctable with optical devices. Patients with severe nutritional deprivation or vitamin B12 deficiency may experience simulated amblyopia. Complete recovery is possible with good diet and B vitamins, however, prolonged deficiency results in permanent loss of central vision. (Ref: WebMD)