follow Dictionary.com

Your favorite word could be our Word of the Day!

optic disk

optic disk in Medicine

optic disk n.
The small, circular, optically insensitive region in the retina containing no rods or cones, where fibers of the optic nerve emerge from the eyeball. Also called blind spot, optic papilla.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Cite This Source
Encyclopedia Article for optic disk

blind spot

small portion of the visual field of each eye that corresponds to the position of the optic disk (also known as the optic nerve head) within the retina. There are no photoreceptors (i.e., rods or cones) in the optic disk, and, therefore, there is no image detection in this area. The blind spot of the right eye is located to the right of the centre of vision and vice versa in the left eye. With both eyes open, the blind spots are not perceived because the visual fields of the two eyes overlap. Indeed, even with one eye closed, the blind spot can be difficult to detect subjectively because of the ability of the brain to "fill in" or ignore the missing portion of the image

Learn more about blind spot with a free trial on Britannica.com
Encyclopedia Britannica, 2008. Encyclopedia Britannica Online.
Cite This Source

Word of the Day

Word Value for optic

9
11
Scrabble Words With Friends