Adjacent Words

Retina definitions

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Webster's 1828 Dictionary

RET'INA, n. [L. from rete, a net.] In anatomy, one of the coats of the eye, being an expansion of the optic nerve over the bottom of the eye, where the sense of vision is first received.

WordNet (r) 3.0 (2005)

n
1: the innermost light-sensitive membrane covering the back wall of the eyeball; it is continuous with the optic nerve

Merriam Webster's

noun (plural retinas or retinae) Etymology: Middle English rethina, from Medieval Latin retina, probably from Latin rete net Date: 14th century the sensory membrane that lines the eye, is composed of several layers including one containing the rods and cones, and functions as the immediate instrument of vision by receiving the image formed by the lens and converting it into chemical and nervous signals which reach the brain by way of the optic nerve — see eye illustration

Britannica Concise

Layer of nerve tissue covering the back two-thirds of the eyeball. Light focused onto the retina by the lens of the eye stimulates two types of light-sensitive cells: rods, which are sensitive to low light levels, and cones, which provide detailed vision and color perception. Chemical changes in these cells trigger nerve impulses, which are assembled by complex connections among retinal nerves into a pattern to be carried through the optic nerve to the visual centers of the brain. Disorders affecting the retina or the macula in its center decrease vision and can cause blindness. See also detached retina, macular degeneration.

Oxford Reference Dictionary

n. (pl. retinas, retinae) a layer at the back of the eyeball sensitive to light, and triggering nerve impulses via the optic nerve to the brain where the visual image is formed. Derivatives: retinal adj. Etymology: ME f. med.L f. L rete net

Webster's 1913 Dictionary

Retina Ret"i*na, n. [NL., from L. rete a net. Cf. Reticule.] (Anat.) The delicate membrane by which the back part of the globe of the eye is lined, and in which the fibers of the optic nerve terminate. See Eye. Note: The fibers of the optic nerve and the retinal blood vessels spread out upon the front surface of the retina, while the sensory layer (called Jacob's membrane), containing the rods and cones, is on the back side, next the choroid coat.

Collin's Cobuild Dictionary

(retinas) Your retina is the area at the back of your eye. It receives the image that you see and then sends the image to your brain. N-COUNT

Moby Thesaurus

baby blues, banjo eyes, bright eyes, clear eyes, cornea, eye, eyeball, eyelid, goggle eyes, iris, lens, lid, naked eye, nictitating membrane, oculus, optic, optic nerve, orb, organ of vision, peeper, popeyes, pupil, saucer eyes, sclera, starry orbs, unaided eye, visual organ