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

While the study points toward using the retina as a way to diagnose and monitor the disease, the researcher acknowledged that more research is needed to confirm these findings. —Amy McGorry, FOXNews.com, 18 Feb. 2026

But in people with myopia, Weidmayer explains, light focuses in front of the retina, resulting in distant objects appearing blurry and close-up objects being clear. —Daryl Austin, USA Today, 17 Feb. 2026

These mini-retinas pointed out that the specific cellular mechanisms arrange red, green, and blue cone cells, noting that the foveola uniquely excludes blue cones to maximize visual clarity. —Mrigakshi Dixit, Interesting Engineering, 16 Feb. 2026

In human retinas, cone cells enable us to see in bright environments, detecting color and fine detail, while rods are sensitive to low light, enabling us to see in the dark. —Jackie Flynn Mogensen, Scientific American, 11 Feb. 2026

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