retina

noun

ret·​i·​na ˈre-tə-nə 

ˈret-nə

plural retinas also retinae ˈre-tə-ˌnē 

-ˌnī

: 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

Examples of retina in a Sentence

Recent Examples on the Web

How Exercise Affects Eye Health The retina, a light-sensitive tissue in the back of the eye, relies on a steady blood supply to function. —Stephanie Brown, Verywell Health, 11 Sep. 2025

Ditto the Hammer Studios output of the 1950s and ’60s, Bernie Wrightson’s definitive illustrations of the Creature, oodles of Gothic literature, Roger Corman’s Poe pictures, and Mario Bava’s retina-searing color creep shows. —David Fear, Rolling Stone, 9 Sep. 2025

Visitors who get verified on-site by allowing the Orb to scan their retinas (no purchase necessary) will unlock access to a prize wheel; but while supplies lasted, everyone left with an item of some sort, according to the company. —Tanya Benedicto Klich, Forbes.com, 9 Sep. 2025

Indiana's offense is activated by his retina scan, though the lineups without him — those composed of players assembled with him in mind — hardly seemed to dip. —Alex Kirschenbaum, MSNBC Newsweek, 29 Aug. 2025

Word History

Etymology

Middle English rethina, from Medieval Latin retina, probably from Latin rete net

First Known Use

14th century, in the meaning defined above

Kids Definition

retina

noun

ret·​i·​na ˈret-ᵊn-ə 

ˈret-nə

plural retinas also retinae -ᵊn-ˌē 

-ˌī

: the light-sensitive inner layer lining the back of the eye that contains the rods and cones and converts the images formed by the lens into signals which reach the brain by way of the optic nerve

retinal

-ᵊn-əl

-nəl

adjective

Medical Definition

retina

1 of 2 noun

ret·​i·​na ˈret-ᵊn-ə, ˈret-nə 

plural retinas also retinae -ᵊn-ˌē 

: the sensory membrane that lines most of the large posterior chamber of the vertebrate 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

Retin-A

2 of 2 trademark

Ret·​in-A ˌret-ᵊn-ˈā 

—used for a preparation of tretinoin