Table of ContentsView AllTable of ContentsAnatomyFunctionAssociated ConditionsTreatmentFrequently Asked Questions
Table of ContentsView All
View All
Table of Contents
Anatomy
Function
Associated Conditions
Treatment
Frequently Asked Questions
Made of nerve cells, the optic nerve is located in the back of the eye. Also known as the second cranial nerve or cranial nerve II, it is the second of several pairs ofcranial nerves. It is a bundle of nerve cells that transmits sensory information for vision in the form of electrical impulses from the eye to the brain. The optic nerve has been studied heavily because it is a direct extension of the brain.
The optic nerve is mainly made up of the axons (nerve fibers) of the retinal ganglion cells from theretina. The optic disc or nerve head is the point where the axons from the retinal ganglion cells leave the eye.
The nerve head appears as a white circular structure in the back of the eye. There are no photoreceptors on this structure. As a result, humans have a natural blind spot.
Nerve cells travel from the nerve head through a structure called the lamina cribrosa that allows the nerve fibers to pass through many holes and into the extraocular (outside of the eyeball) space. As the fibers pass through, they become covered with a type of insulation called myelin. The nerve fibers become insulated with glial cells known as oligodendrocytes.
Location
As the optic nerves exit the eye they join together at theoptic chiasm. At the optic chiasm, nerve fibers from half of the retina cross over to the opposite side of the brain. The fibers from the other half of the retina travel to the same side of the brain.
Because of this junction, each half of the brain receives visual signals from the visual fields of both eyes. The chiasm is located at the bottom of the brain.
After the chiasm, the nerve fibers extend to the lateral geniculate nucleus (LGN) in the thalamus. From there, the nerve fiber tracts extend from the LGN into optic radiation fibers that fan through different parts of the brain including the parietal lobe, temporal lobe, and occipital lobe.
Knowledge of the pathway of the optic nerve from the eye to the brain is important because the origin of different diseases that affect vision can be localized based upon the location of the defect in vision or where in the visual field a defect may show up.
The optic nerve produces all sorts of visual information.
The perception of brightness, color perception, and contrast are all possible because of the optic nerve.
There are several diseases that can affect the optic nerve, chiasma, and radiations, including:
Glaucoma
Glaucomarefers to a group of diseases that may cause damage to the optic nerve. The optic nerve fibers make up a part of the retina that gives us sight. This nerve fiber layer can be damaged when the pressure of the eye (intraocular pressure) becomes too high.
Over time, high pressure causes the nerve fibers to die, resulting in decreased vision. Vision loss and blindness will likely result if glaucoma is left untreated.
Optic Neuritis
Optic neuritisis an inflammation of the optic nerve. This often affects only one eye at a time and affects the part of the nerve before the optic chiasm. Because of the location of the inflammation, one would predict that problems will show up in the vision of just one eye.
Verywell / Cindy Chung
Pituitary Adenoma
The pituitary gland is located underneath the optic chiasm. If the pituitary gland grows large or develops a mass or growth, it can press on the optic chiasm causing defects in both visual fields because the nerve fibers cross at the chiasm.
Vascular Infarcts and Aneurysms
Vascular diseases (diseases that affect blood vessels) can cause problems along the pathway of the optic radiations. Because the optic radiation nerve fibers pass through the parietal lobe, temporal lobe, and occipital lobe of the brain, defects or blind spots can develop in the visual field. The location of the defect in the visual field can tell doctors where in the brain to look for the problem.
Treatment of optic nerve damage, chiasma or optic radiation damage depends on the cause. However, treatments for optic nerve damage may not restore lost sight. In most cases, measures are taken to stop further damage and worsening of symptoms. For example:
Frequently Asked QuestionsOne of the most important nerves in the upper body, the optic nerve connects the eyeball and the brain.It’s responsible for carrying messages between the eye and brain. It’s comprised of four parts: intraocular, intraorbital, intracanalicular, and intracranial.Learn MoreAl About the Cranial NervesYes. There are neuroprotective glaucoma medications that work to protect the nerve.With these medications, you may be able to prevent vision loss. These drugs include carbonic anhydrase inhibitors and prostaglandin analogs that can lower intraocular pressure.Learn MoreWhat You Should Know About GlaucomaNo. Damage to the nerve cannot be reversed, but researchers continue to look for ways to do so.There are treatments, though, that can help manage optic nerve damage. Catching issues early is the best way to prevent problems from becoming worse.Learn MoreHow Does Your Doctor Check You For Glaucoma?
One of the most important nerves in the upper body, the optic nerve connects the eyeball and the brain.It’s responsible for carrying messages between the eye and brain. It’s comprised of four parts: intraocular, intraorbital, intracanalicular, and intracranial.Learn MoreAl About the Cranial Nerves
One of the most important nerves in the upper body, the optic nerve connects the eyeball and the brain.It’s responsible for carrying messages between the eye and brain. It’s comprised of four parts: intraocular, intraorbital, intracanalicular, and intracranial.
Learn MoreAl About the Cranial Nerves
Yes. There are neuroprotective glaucoma medications that work to protect the nerve.With these medications, you may be able to prevent vision loss. These drugs include carbonic anhydrase inhibitors and prostaglandin analogs that can lower intraocular pressure.Learn MoreWhat You Should Know About Glaucoma
Yes. There are neuroprotective glaucoma medications that work to protect the nerve.With these medications, you may be able to prevent vision loss. These drugs include carbonic anhydrase inhibitors and prostaglandin analogs that can lower intraocular pressure.
Learn MoreWhat You Should Know About Glaucoma
No. Damage to the nerve cannot be reversed, but researchers continue to look for ways to do so.There are treatments, though, that can help manage optic nerve damage. Catching issues early is the best way to prevent problems from becoming worse.Learn MoreHow Does Your Doctor Check You For Glaucoma?
No. Damage to the nerve cannot be reversed, but researchers continue to look for ways to do so.There are treatments, though, that can help manage optic nerve damage. Catching issues early is the best way to prevent problems from becoming worse.
Learn MoreHow Does Your Doctor Check You For Glaucoma?
7 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Smith AM, Czyz CN.Neuroanatomy, cranial nerve 2 (optic). In: StatPearls.Garrity J.Overview of optic nerve disorders. Merck Manual Consumer Version.Dietze J, Havens SJ.Glaucoma. In: StatPearls.Gossman W, Ehsan M, Xixis KL.Multiple sclerosis. In: StatPearls.American Academy of Ophthalmology.Optic Nerve.American Academy of Ophthalmology.Neuroprotection in Glaucoma.Glaucoma Research Foundation.Imaging of the Optic Nerve: What is it and why is it needed?Additional ReadingAmerican Academy of Ophthalmology.Optic Nerve.Margolin E, Shemesh A.Optic neuropathy, toxic and nutritional. In: StatPearls. Treasure Island (FL): StatPearls Publishing.MedlinePlus. U.S. National Library of Medicine.Optic Nerve Disorders.
7 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Smith AM, Czyz CN.Neuroanatomy, cranial nerve 2 (optic). In: StatPearls.Garrity J.Overview of optic nerve disorders. Merck Manual Consumer Version.Dietze J, Havens SJ.Glaucoma. In: StatPearls.Gossman W, Ehsan M, Xixis KL.Multiple sclerosis. In: StatPearls.American Academy of Ophthalmology.Optic Nerve.American Academy of Ophthalmology.Neuroprotection in Glaucoma.Glaucoma Research Foundation.Imaging of the Optic Nerve: What is it and why is it needed?Additional ReadingAmerican Academy of Ophthalmology.Optic Nerve.Margolin E, Shemesh A.Optic neuropathy, toxic and nutritional. In: StatPearls. Treasure Island (FL): StatPearls Publishing.MedlinePlus. U.S. National Library of Medicine.Optic Nerve Disorders.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Smith AM, Czyz CN.Neuroanatomy, cranial nerve 2 (optic). In: StatPearls.Garrity J.Overview of optic nerve disorders. Merck Manual Consumer Version.Dietze J, Havens SJ.Glaucoma. In: StatPearls.Gossman W, Ehsan M, Xixis KL.Multiple sclerosis. In: StatPearls.American Academy of Ophthalmology.Optic Nerve.American Academy of Ophthalmology.Neuroprotection in Glaucoma.Glaucoma Research Foundation.Imaging of the Optic Nerve: What is it and why is it needed?
Smith AM, Czyz CN.Neuroanatomy, cranial nerve 2 (optic). In: StatPearls.
Garrity J.Overview of optic nerve disorders. Merck Manual Consumer Version.
Dietze J, Havens SJ.Glaucoma. In: StatPearls.
Gossman W, Ehsan M, Xixis KL.Multiple sclerosis. In: StatPearls.
American Academy of Ophthalmology.Optic Nerve.
American Academy of Ophthalmology.Neuroprotection in Glaucoma.
Glaucoma Research Foundation.Imaging of the Optic Nerve: What is it and why is it needed?
American Academy of Ophthalmology.Optic Nerve.Margolin E, Shemesh A.Optic neuropathy, toxic and nutritional. In: StatPearls. Treasure Island (FL): StatPearls Publishing.MedlinePlus. U.S. National Library of Medicine.Optic Nerve Disorders.
Margolin E, Shemesh A.Optic neuropathy, toxic and nutritional. In: StatPearls. Treasure Island (FL): StatPearls Publishing.
MedlinePlus. U.S. National Library of Medicine.Optic Nerve Disorders.
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