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

This helps assess the retina's thickness and detect signs of macular degeneration and new blood vessel growth. —Mark Gurarie, Verywell Health, 7 Apr. 2025

In some cases, similar forces occur in the back of the eye, and hemorrhages in the retina can occur. —Lori Frasier, The Conversation, 19 Mar. 2025

On the other hand, proper viewing glasses and other necessary safety precautions are important while observing a solar eclipse as the powerful rays of the sun can burn and damage your retinas. —Saman Shafiq, USA TODAY, 13 Mar. 2025

Then a solution containing the viral vector is injected under the retina so that the virus can get to work installing the new genetic code into the photoreceptor cells. —Tom Rogers, Newsweek, 21 Feb. 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