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

Staring straight at the Sun during partial and annular solar eclipses can cause permanent damage to the retina, according to the American Astronomical Society. More from Axios: Egg prices plunging as bird flu subsides and shortages dissipate Kohl's closing underperforming stores this Saturday. —Kelly Tyko, Axios, 29 Mar. 2025

Take only brief looks and don't stare long enough for infrared rays to build up heat on your retina. —Joe Rao, Space.com, 28 Mar. 2025

Caffey linked permanent brain damage and bleeding in the backs of the retina to violent shaking of infants. —Lori Frasier, The Conversation, 19 Mar. 2025

Overall, the findings, published in February in the Journal of Imaging, suggest the retina could be a long Covid biomarker. —Katie Camero, NBC News, 11 Mar. 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