- 1 What is the optic nerve and its function?
- 2 How do you describe the optic nerve?
- 3 What are signs of optic nerve damage?
- 4 What does optic nerve supply?
- 5 How do you test optic nerve function?
- 6 How is optic nerve formed?
- 7 What is optic nerve damage?
- 8 Can you see your optic nerve?
- 9 What happens if you cut the left optic nerve?
- 10 What is the treatment for optic nerve damage?
- 11 How do you fix optic nerve damage?
- 12 How do you get optic nerve damage?
- 13 Why optic nerve is not a true cranial nerve?
- 14 Why is the optic nerve white?
- 15 Why does the optic nerve crossover?
What is the optic nerve and its function?
The Optic Nerve or Cranial Nerve II
The optic nerve is a special sensory nerve that carries information from the visual world to the brain. Embryologically, the optic nerve is derived from an outgrowth of the forebrain; therefore, it is part of the central nervous system (CNS) and is composed of CNS fiber tracts.
How do you describe the optic nerve?
Optic nerve: The optic nerve connects the eye to the brain. The optic nerve carries the impulses formed by the retina, the nerve layer that lines the back of the eye and senses light and creates impulses. These impulses are dispatched through the optic nerve to the brain, which interprets them as images.
What are signs of optic nerve damage?
While there are several potential causes of optic neuropathy, some of the most common symptoms include:
- Pain in the eyes.
- Loss of peripheral vision, or the sides of the visual field.
- Loss of color vision.
- Flashing lights called.
- Loss of sight in one eye but not the other.
- Double vision.
- Pain in the eye socket or face.
What does optic nerve supply?
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.
How do you test optic nerve function?
Two common imaging tests include a simple high-resolution color photograph with a very bright flash from a professional camera, and a quick laser scan of the optic nerve. Scans can detect small nerve fiber layer changes of the optic nerve at the micron level.
How is optic nerve formed?
The optic nerve is formed by the convergence of axons from the retinal ganglion cells. These cells in turn receive impulses from the photoreceptors of the eye (the rods and cones). After its formation, the nerve leaves the bony orbit via the optic canal, a passageway through the sphenoid bone.
What is optic nerve damage?
Optic nerve damage is any kind of injury or damage to the optic nerve, including trauma, inflammation, disease or deterioration. Optic nerve damage is also called optic nerve atrophy or optic neuropathy. The optic nerve is the nerve that connects and transmits information between the eye and the brain.
Can you see your optic nerve?
The spot where your optic nerve connects to your retina has no light-sensitive cells, so you can‘t see anything there.
What happens if you cut the left optic nerve?
The entire left optic nerve would be cut and there would be a total loss of vision from the left eye. Damage at site #2: partial damage to the left optic nerve. Here, information from the nasal visual field of the left eye (temporal part of the left retina) is lost. Damage at site #3: the optic chiasm would be damaged.
What is the treatment for optic nerve damage?
Optic neuritis usually improves on its own. In some cases, steroid medications are used to reduce inflammation in the optic nerve. Possible side effects from steroid treatment include weight gain, mood changes, facial flushing, stomach upset and insomnia. Steroid treatment is usually given by vein (intravenously).
How do you fix optic nerve damage?
Optic Nerve Damage Treatment
- For people diagnose with glaucoma, treatment may involve use of eye drops, oral medications or getting eye surgeries like laser therapy or drainage tubes.
- For people suffering from Optic Nerve drusen, may benefit from medication that lowers intraocular pressure.
How do you get optic nerve damage?
The problem most often affects older adults. The optic nerve can also be damaged by shock, toxins, radiation, and trauma. Eye diseases, such as glaucoma, can also cause a form of optic nerve atrophy. The condition can also be caused by diseases of the brain and central nervous system.
Why optic nerve is not a true cranial nerve?
The optic nerve (II) is not a true nerve but is actually an extension of a brain tract; in fact, II is myelinated by oligodendrocytes rather than Schwann cells. Therefore, cranial nerves I and II are part of the CNS, and the rest are considered part of the PNS.
Why is the optic nerve white?
Atrophy to the optic nerve occurs when there is degeneration to the axons of the nerve. This results in recession and loss of the micro-capillary networks that supply the optic nerve. Sometimes the optic nerve can transition from being normal and healthy to having a pale/atrophic appearance.
Why does the optic nerve crossover?
The partial crossing over of optic nerve fibres at the optic chiasm allows the visual cortex to receive the same hemispheric visual field from both eyes. Superimposing and processing these monocular visual signals allow the visual cortex to generate binocular and stereoscopic vision.