iris vs oculus

iris and oculus both are nouns.

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

iris (noun)	oculus (noun)
diaphragm consisting of thin overlapping plates that can be adjusted to change the diameter of a central opening	the organ of sight
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