Pronunciation: (ret'n-ul),[key] —adj. of or pertaining to the retina of the eye.
Pronunciation: (ret'n-al", -ôl"),[key] —n.Biochem. 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•nenePronunciation: (ret'n-ēn").[key]