Recent articles in the scientific literature have described major advances in our understanding of the anatomy and vascular relationships of the optic nerve (cranial nerve II) and of the diagnosis and treatment of a variety of disorders affecting this nerve, including congenital anomalies of the optic disc, dominant hereditary optic neuropathy, anterior and retrobulbar arteritic and nonarteritic ischemic optic neuropathy, optic neuritis, Cuban epidemic optic neuropathy, toxic and nutritional optic neuropathies, radiation-induced optic neuropathy, AIDS-related optic neuropathy, optic neuropathies caused by tumors, and papilledema.