Noun | 1. | retinal - either of two yellow to red retinal pigments formed from rhodopsin by the action of light pigment - dry coloring material (especially a powder to be mixed with a liquid to produce paint, etc.) retinal purple, rhodopsin, visual purple - a red photopigment in the retinal rods of vertebrates; dissociates into retinene by light |
Adj. | 1. | retinal - in or relating to the retina of the eye; "retinal cells" |