oculus vs iris

oculus and iris both are nouns.

Word	Noun	Adjective	Verb	Adverb
oculus	Yes	No	No	No
iris	Yes	No	No	No

oculus (noun)	iris (noun)
the organ of sight	diaphragm consisting of thin overlapping plates that can be adjusted to change the diameter of a central opening
	muscular diaphragm that controls the size of the pupil which in turn controls the amount of light that enters the eye; it forms the colored portion of the eye
	plants with sword-shaped leaves and erect stalks bearing bright-colored flowers composed of three petals and three drooping sepals