noun, plural: optic nerves
The cranial nerve that carry impulses for the sense of sight (vision)
Cranial nerves are paired nerves that emerge from the brain and the brainstem. They supply the motor pathways between organs in the face and the upper body, and account for detecting and processing various sensations. One of the cranial nerves is the optic nerve. The optic nerve, also referred to as cranial nerve II (CN II), is a paired nerve that carries impulses for the sense of sight. It projects from the vertebrate retina to the midbrain. It is structurally more apt as part of the central nervous system than of the peripheral nervous system.
It is popularly used in experimental preparation for studies in the regeneration of retino tectal projections in lower vertebrates. It is also used for studies of glial cell lineage in the central nervous system. It is derived from the optic stalks during the seventh week of embryological development. It is composed of retinal ganglion cell axons and glial cells.
Since the optic nerve is involved in sending visual information, damage to this nerve may result in vision limitations. For instance, in homonymous hemianopsia, the individual may fail to see objects on the left or right sides.
- cranial nerve II (CN II)