retinal¹

[ret-n-uh l]

adjective

Origin of retinal¹

First recorded in 1830–40; retin(a) + -al¹

[ret-n-al, -awl]

noun Biochemistry.

an orange pigment, C20H28O, that is the active component of rhodopsin and is liberated upon the absorption of light in the vision cycle; vitamin A aldehyde.

Also ret·i·nene

[ret-n-een] /ˈrɛt nˌin/.

First recorded in 1940–45; retin(a) + -al³

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

To complement brain wiring, everyone walks around with retinal cams.
The Internet Embedded in Your Head
J.T. Price
November 21, 2014

Mike the Angel put his face in the rest for the retinal photos.
Unwise Child
Gordon Randall Garrett
“Such as fingerprint and retinal patterns,” said Lieutenant Nariaki.
Unwise Child
Gordon Randall Garrett
Retinal pattern 490-BJ4-67—which is also the code that is supposed to get me through your blockade.
Planet of the Damned
Harry Harrison
This is generally accounted for by fatigue of the retinal process.
Visual Illusions
Matthew Luckiesh
The retinal image of the object is not only vague, but also distorted.
Clever Hans
Oskar Pfungst

1838; see retina + -al (1).

retinal in Medicine

(rĕt′n-ăl′, -ôl′)