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

In addition to its antioxidant properties, zinc also exists in the retina in high concentrations.1 6. —Melissa Nieves, Verywell Health, 4 June 2025

Her dog's facial hair, including eyelashes, was shaved, and surgeons made two small incisions at the sides of her eyes to access the retina. —Lydia Patrick, MSNBC Newsweek, 30 May 2025

Some might collect biometric data such as fingerprints and retina scans as part of efforts to improve security. —Andrew Park, Harvard Business Review, 29 May 2025

This made the humpback’s focal length—the distance between the eye’s lens and retina—shorter than expected, as Bolin tells bioGraphic’s Marina Wang. —Margherita Bassi, Smithsonian Magazine, 21 May 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