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

The mainstay of the AI law is to set boundaries on AI and the use of biometric data such as fingerprints, eye retina recordings, and voiceprints, though this is aimed at government entities and not necessarily private sector organizations, and to prohibit using AI in untoward ways. —Lance Eliot, Forbes.com, 25 Jan. 2026

There have been case studies of negative effects to tissues in the head (like a torn retina) when people stood on these with straight legs. —Jennifer Heimlich, Time, 23 Jan. 2026

Biologists have finally solved a centuries-old mystery regarding how birds maintain sharp eyesight despite their retinas lacking a direct blood supply. —Mrigakshi Dixit, Interesting Engineering, 21 Jan. 2026

Beyond peripheral nerves and the retina, researchers are exploring whether optogenetics could one day help suppress seizures in hard-to-treat epilepsy or modulate abnormal activity in movement disorders such as Parkinson’s disease. —New Atlas, 16 Jan. 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