optic disk

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Related to optic disk: optic cup, fovea


a circular or rounded flat plate; often spelled disc in names of anatomic structures.
articular disk a pad of fibrocartilage or dense fibrous tissue present in some synovial joints.
Bowman's disk one of the flat plates making up a striated muscle fiber.
choked disk papilledema.
ciliary disk pars plana.
embryonic disk (germ disk) (germinal disk) a flattened round bilaminar plate of cells in the blastocyst of a mammal, where the first traces of the embryo are seen; called also embryonic or germinal area.
herniated disk see herniated disk.
intervertebral disk the layer of fibrocartilage between the bodies of adjoining vertebrae; see also herniated disk.
intra-articular d's articular disk.
Merkel's d's small cup-shaped tactile receptors in the skin that are particularly sensitive to continuous pressure.
optic disk the intraocular part of the optic nerve formed by fibers converging from the retina and appearing as a pink to white disk in the retina; there are no sensory receptors in the region and hence no response to stimuli. Called also blind spot.
ruptured disk herniated disk.
slipped disk popular term for herniated disk.

optic disk

n. Anatomy

Optic disk

The small area in the retina where the optic nerve enters the eye that is not sensitive to light. Also called the blind spot.


Edmé, French physicist, 1620-1684.
Mariotte blind spot - an oval area of the ocular fundus devoid of light receptors where the axons of the retinal ganglion cell converge to form the optic nerve head. Synonym(s): optic disk
Mariotte bottle - a stoppered bottle with bottom outlet, used as a reservoir for constant infusions.
Mariotte experiment - an experiment that proves the absence of photoreceptors where the optic nerve enters the eye.
Mariotte law - Synonym(s): Boyle law


of or pertaining to the eye.

optic chiasma
see optic chiasm.
optic cortex
see visual cortex.
optic cup activity
optic disk
the disk in the fundus of the eye marking the point at which the optic nerve enters; it is accompanied by blood vessels, is oval, light in color and the blind spot of the retina.
optic nerve
the second cranial nerve; it is purely sensory and is concerned with carrying impulses for the sense of sight. The rods and cones of the retina are connected with the optic nerve which leaves the eye slightly to the nasal side of the center of the retina. The point at which the optic nerve leaves the eye is called the blind spot because there are no rods and cones in this area. The optic nerve passes through the optic foramen of the skull and into the cranial cavity. It then passes backward and undergoes a division; those nerve fibers leading from the nasal side of the retina cross to the opposite side in the optic chiasma while those from the temporal side continue to the thalamus uncrossed. The nerve tracts proceeding backward from the optic chiasm, pass around the cerebral peduncle, and dividing into a lateral and medial root, which end in the superior colliculus and lateral geniculate body, respectively. After synapsing in the thalamus the neurons convey visual impulses to the occipital lobe of the brain.
Injury to the nerve leads to partial or complete loss of sight on the opposite side. Commonly bilateral.
optic nerve aplasia
an uncommon congenital anomaly, most frequently seen in Collie dogs; affected animals are blind from birth. Hypovitaminosis A and prenatal infection with bovine virus diarrhea are possible causes.
optic nerve inflammation
optic neuritis.
optic primordia
the eyes begin in the embryo as a pair of shallow optic grooves on each side of the developing forebrain. The grooves form optic vesicles which invaginate to form a double-walled optic cup.
optic radiation
fibers from the lateral geniculate body entering the occipital cortex.
optic stalk
the evagination from the neural tube of the developing embryo which develops the optic cup at its extremity; the stalk persists as the optic nerve.
optic sulcus
see optic groove.
optic vesicle
the initial evagination from the neural tube which gives rise to the optic cup and the optic stalk.
References in periodicals archive ?
Experimentally, we found that the bright pixels forming the optic disk were in the range of 15 % to 20 % of the brightest pixel set in the whole image.
The results were 469 images with correct optic disk localization and 22 with misplaced optic disk localization.
In general, we did not expect an improvement in the accuracy of optic disk localization with regard to the sequential model.
ES based on bright and vessel border pixels for optic disk localization showed an accuracy of 96 %.
The purpose of this study was to investigate the peri-papillary retinal nerve fiber layer thickness using HRT in patients with anisometropic amblyopia to identify if amblyopia is associated with changes in optic disk morphology.
The optic disk contour was subsequently drawn by a doctor who was experienced and was blind to the study.
Changes in the morphology of RNFLT, as indicated by its thickness, may help establish an association between changes in optic disk morphology and amblyopia.
This is in agreement with published literature when assessing optic disk by HRT for ambylopia.
You can locate the optic disk by noting where the blood vessels originate or the blue arcs terminate in Activities 6 and 10, respectively If you keep one eye closed and blink with the other eye while looking at a uniformly illuminated surface (such as the inner surface of a ping pong ball cut in half to fit over the eye), you may see a gray disk at the location of the optic disk (Palmer, 1991).
Drusen of the optic disk and aberrant axoplasmic transport.