Knowra Optic nerve Optic nerve The optic nerve is the second cranial nerve, carrying visual signals from retinal ganglion cells to the brain. It is part of the central nervous system and is surrounded by the meninges.
Retinal ganglion cell : A retinal neuron whose axon carries visual signals toward the brain. Their axons bundle together to form the optic nerve.
Retina : The light-sensitive neural tissue lining the back of the eye. It converts light into neural signals that feed the optic nerve.
Optic neuritis : Inflammation of the optic nerve that can cause pain and impaired vision. It is a common optic nerve disorder, sometimes associated with multiple sclerosis.
Oculomotor nerve : The third cranial nerve, controlling most eye movements, eyelid elevation, and pupil constriction. Unlike the optic nerve, it carries motor and parasympathetic commands rather than visual input.
Optic chiasm : A junction where fibers from the nasal halves of the retinas cross to the opposite side of the brain. Some optic nerve fibers cross here before continuing into the optic tracts.
Photoreceptor cell : A retinal cell, such as a rod or cone, that converts light into electrical and chemical signals. Photoreceptors begin the visual signal chain that ultimately reaches the nerve.
Glaucoma : A group of eye diseases that damage the optic nerve, often alongside elevated intraocular pressure. Its characteristic nerve damage can progressively reduce the visual field.
Olfactory nerve : The first cranial nerve, conveying smell information from the nasal cavity to the brain. It is another sensory cranial nerve, but serves smell rather than vision.
Optic tract : A bundle of visual pathway fibers extending from the optic chiasm toward the brain's visual processing centers. It carries the nerve's signals beyond the chiasm toward the thalamus and midbrain.
Rod cell : A retinal photoreceptor specialized for vision in dim light. Rod signals pass through retinal circuits before entering the optic nerve.
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