rhodopsin vs visual purple

rhodopsin and visual purple both are nouns.

Word	Noun	Adjective	Verb	Adverb
rhodopsin	Yes	No	No	No
visual purple	Yes	No	No	No

As nouns, rhodopsin and visual purple are synonyms defined as:

rhodopsin and visual purple: a red photopigment in the retinal rods of vertebrates; dissociates into retinene by light

Other synonyms of rhodopsin include retinal purple.

rhodopsin (noun)	visual purple (noun)
a red photopigment in the retinal rods of vertebrates; dissociates into retinene by light	a red photopigment in the retinal rods of vertebrates; dissociates into retinene by light