cranial nerve II

Last reviewed 01/2018

The optic nerve forms part of the visual pathway; sensory impulses are transmitted along the optic nerve to the optic chiasma.

The optic nerve may be torn or compressed by fractures involving the orbital walls. There is usually an immediate onset of blindness. Optic atrophy will become visible within days.

Compression of the optic nerve by pituitary tumours can produce a bitemporal hemianopia - a loss of the lateral half of the visual fields in both eyes.

Blindness beyond a certain circumference of the visual field may indicate inflammation of the nerve, as in optic neuritis.