<unk>  is a group of medical disorders defined by visual impairment due to optic nerve damage secondary to a<unk>  substance and/or<unk>  deficiency. The causes of these disorders are various, but they are linked by shared signs and symptoms, which this article will describe. In several of these disorders, both<unk>  and<unk>  factors play a role, acting synergistically.
Toxic and nutritional optic neuropathy
Chronic relapsing inflammatory optic neuropathy
Autoimmune optic neuropathy
Arteritic anterior ischemic optic neuropathy
Ischemic optic neuropathy
Posterior ischemic optic neuropathy
Kjer's optic neuropathy
Late congenital syphilitic oculopathy