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

Ozog warns that prolonged exposure to red or infrared light could damage your retina. —Maria Godoy, NPR, 13 Apr. 2026

Retinoblastoma is a rare eye cancer that originates in the retina and usually affects children under the age of 4, according to the Children’s Hospital of Philadelphia. —Kimberlee Speakman, PEOPLE, 12 Apr. 2026

During Monday’s lunar flyby, the moon will be between the Orion capsule and the sun, blotting out its retina-burning light so that MAPS’s fainter glow can be safely seen. —Meghan Bartels, Scientific American, 3 Apr. 2026

Anatomically, the retina is an extension of the posterior part of the brain. —IEEE Spectrum, 2 Apr. 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