Optic neuritis is a kind of pathogenic change of the optic nerve which is characterized by diminishment of vision and the corresponding changes of visual field. Because the damaged part of lesion is different, the disease is divided into two types: intraglomerular  papillitis of the optic nerve and retrobulbar neuritis. The latter, according to the greater or less emergency of inflammation, is again classified into the acute and chronic cases. The main manifestations of the disease in clinic are abrupt diminishment of vision and even blindness. Common in the young and middle-aged, it can sometimes be seen in children but less in the aged.  It often occurs monocularly and some times binocularly and develops rather rapidly with the vision severely damaged.