optic nerve

Also found in: Dictionary, Thesaurus, Medical, Financial, Wikipedia.

optic nerve:

see visionvision,
physiological sense of sight by which the form, color, size, movements, and distance of objects are perceived. Vision in Humans

The human eye functions somewhat like a camera; that is, it receives and focuses light upon a photosensitive receiver, the retina.
..... Click the link for more information.
The Columbia Electronic Encyclopedia™ Copyright © 2013, Columbia University Press. Licensed from Columbia University Press. All rights reserved. www.cc.columbia.edu/cu/cup/
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Optic Nerve


(nervus opticus), the second pair of cranial nerves, along which visual stimuli received by the sensory cells of the retina are transmitted to the brain.

The optic nerve is not a typical cranial nerve in structure, but is like brain matter transported to the periphery and connected with the nuclei of the diencephalon, and through them also with the cortex of the large hemispheres. The optic nerve originates in the ganglial cells of the retina. Processes of these cells gather into the optic disk (or papilla), which is located 3 mm closer to the middle from the posterior pole of the eye. Farther on, the bundles of nerve fibers penetrate the sclera in the region of the lamina cribrosa and are surrounded by meningeal structures, forming a compact nerve trunk. Located among the bundles of fibers of the optic nerve are the central artery of the retina and the analogous vein. Together with the ophthalmic artery, the optic nerve passes into the cranial cavity through the optic canal, which is formed by a small wing of the sphenoid bone. Within the cranial cavity, the optic nerve goes from each eye toward the posterior and closer to the middle for about 1 cm, and then approaches the optic nerve of the opposite side over the sella turcica of the sphenoid bone; anterior to the hypophysis the optic chiasma is formed, where there is a crossover only of the axons of the cells of the nasal half of the retina. After the chiasma, the optic nerve continues into the optic tracts.


The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

optic nerve

[′äp·tik ‚nərv]
The second cranial nerve; a paired sensory nerve technically consisting of three layers of special nerve cells in the retina of the eye; fibers converge to form the optic tracts.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
In a study with retrobulbar meningiomas, all tumors were caudal to the ocular bulb and in 54.5% of them, the optic nerve could not be located due to the total involvement by the mass (MAULDIN, et al., 2000).
Ultrasound measurements of the optic nerve sheath diameter (ONSD) were not used to make treatment decisions during this phase of the study.
She also pointed out findings in a case report of a patient without microcephaly but with a circular hypopigmented lesion superior to the optic nerve on the fundus of the left eye (12).
We also know that what we eat or do not eat may cause problems for our optic nerves! Badly processed cassava, excessive use of medicines such as Chloroquine or Quinine, toxic alcohols and herbal concoctions are well known to cause severe damage to the optic nerves.
Your eye doctor will assess your colour vision, peripheral vision, pupil reaction to light, visual acuity, and will also look inside your eye with an instrument called an ophthalmoscope to determine whether your optic nerve appears pale.
The optic nerve is a cranial nerve that is technically a part of the central nervous system because of its embryological derivation as an outpouching of the diencephalon.
The doctor measures the pressure of the eye and examines the optic nerve in the eye.
The International Optic Nerve Trauma Study (IONTS) group found no significant difference in visual acuity outcome between treated and untreated patients, with the conclusion that neither form of available treatment can be recommended as the preferred option.
Avulsion of the optic nerve is a rare complication after ocular trauma but carries a poor prognosis.
We are the only actively recruiting stem cell study in retina or optic nerve that has publications about actual study results listed on the clinicaltrials.gov site."
Several high-risk factors documented to be associated with extraocular recurrence have been identified upon Histopathological (HP) examination of enucleated eyes, which include invasion of post-laminar optic nerve, trans-scleral migration, choroidal invasion and anterior chamber seeding.