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

Human retinas typically have three types of cone cells, which are what allow our eyes to detect various wavelengths of light. —Sara Hashemi, Smithsonian Magazine, 22 Apr. 2025

Vision and hearing, for instance, are confined to the retina and the cochlea — parts the size of a postage stamp and a pea, respectively. —Ariel Bleicher, Quanta Magazine, 16 Apr. 2025

Damage to your retina can happen without any sensation of pain. —Joe Rao, Space.com, 28 Mar. 2025

The pupil, the dark center of the eye, determines how much light reaches the light-sensing retina at the back of the eye. —Maxine Lipner, Verywell Health, 19 Mar. 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