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 eclipse may cause discomfort — but likely won’t since the retina doesn’t have pain nerves. —Simone Jasper, Miami Herald, 8 Apr. 2024

Compared to regular sunglasses, proper eclipse glasses are 100,000 times darker to block nearly all visible, infrared and ultraviolet light and protect our sensitive retinas when looking skyward. —Eric Lagatta, USA TODAY, 8 Apr. 2024

The American Academy of Ophthalmology says pain won't be an indication of damaged eyes because the retina lacks pain nerves. —The Arizona Republic, 8 Apr. 2024

Looking up with the naked eye or regular sunglasses can burn the retina, leading to long-lasting -- even permanent -- damage. —Mary Kekatos, ABC News, 5 Apr. 2024

Exposure to the sun without proper protection can permanently damage the eye's retina. —Lee V. Gaines, NPR, 25 Mar. 2024

As light dims, our eyes transition from photopic vision, associated with the retina's cone cells that deliver full colors and fine detail, toward scotopic night vision that relies on rod cells to detect objects in low light. —Bill Chappell, NPR, 6 Apr. 2024

Those changes in turn help to limit mechanical strain on the optic nerve head, the funnel through which more than a million nerve fibers from the retina come together to transmit visual signals to the brain. —IEEE Spectrum, 22 Mar. 2024

The retina, a very sensitive part of our eye, is at risk during these events. —George Dvorsky / Gizmodo, Quartz, 13 Mar. 2024

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