eyeball vs orb

eyeball and orb both are nouns.

Word	Noun	Adjective	Verb	Adverb
eyeball	Yes	No	Yes	No
orb	Yes	No	Yes	No

As nouns, eyeball and orb are synonyms defined as:

eyeball (noun)	orb (noun)
the ball-shaped capsule containing the vertebrate eye	the ball-shaped capsule containing the vertebrate eye
	an object with a spherical shape

eyeball (verb)	orb (verb)
look at	move in an orbit