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cross section of the eye
Horizontal cross section of the human eye, showing the structures of the eye, the visual axis (the central point of image focusing in the retina), and the optical axis (the axis about which the eye is rotated by the eye muscles).
optic nerve
anatomy
Also known as: second cranial nerve
- Key People:
- Ragnar Arthur Granit
optic nerve, second cranial nerve, which carries sensory nerve impulses from the more than one million ganglion cells of the retina toward the visual centres in the brain. The vast majority of optic nerve fibres convey information regarding central vision. The optic nerve begins at the optic disk, a structure that is 1.5 mm (0.06 inch) in diameter and is located at the back of the eye. The optic disk forms from the convergence of ganglion cell output fibres (called axons) as they pass out of the eye. When the nerve emerges from the back of the eye, it passes ...(100 of 339 words)