Cranial nerve that is continuous with the layer of nerve cells on the inner surface of the eye. It exits the neurocranium via the large optic foramen and is covered by a fibrous connective tissue sheath. It transmits visual information from the retina to the brain. [ https://www.worldcat.org/search?q=bn%3A080184780X http://purl.obolibrary.org/obo/UBERON_0000941 ]