DefinitionOptic nerve atrophy is tissue death of the nerve that carries the information regarding sight from the eye to the brain.Alternative NamesSecond cranial nerve atrophyCauses, incidence, and risk factorsThere are many unrelated causes of optic atrophy. The most common cause is poor blood flow, called ischemic optic neuropathy, which most often affects the elderly. The optic nerve can also be damaged by shock, various toxic substances, radiation, and trauma.Various eye diseases, most commonly glaucoma, can also cause optic nerve atrophy. In addition, the condition can be caused by diseases of the brain and central nervous system, such as cranial arteritis (sometimes called temporal arteritis), multiple sclerosis, brain tumor, and stroke.There are also several rare forms of hereditary