Cranial nerve II

Cranial Nerve II: The Optic Nerve

The optic nerve and its visual pathway.

The Optic Nerve, also known as Cranial Nerve II, is the second of twelve paired cranial nerves. It is responsible for transmitting visual information from the retina to the brain.

Anatomy

The optic nerve is composed of retinal ganglion cell axons and glial cells. Each human optic nerve contains between 770,000 and 1.7 million nerve fibers, which are axons of the retinal ganglion cells of one retina.

Function

The optic nerve functions as a pure sensory nerve. It transmits visual information from the retina to the brain. This information is processed in the brain's visual cortex to produce the experience of vision.

Clinical significance

Damage to the optic nerve can cause vision loss, because the nerve is crucial for transmitting visual information to the brain. Conditions such as glaucoma, optic neuritis, and optic nerve glioma can cause optic nerve damage.

See also

• Cranial nerves
• Visual system
• Ophthalmology