peephole vs eyehole

peephole and eyehole both are nouns.

Word	Noun	Adjective	Verb	Adverb
peephole	Yes	No	No	No
eyehole	Yes	No	No	No

As nouns, peephole and eyehole are synonyms defined as:

peephole and eyehole: a hole (in a door or an oven etc) through which you can peep

Other synonyms of peephole include spyhole.

peephole (noun)	eyehole (noun)
a hole (in a door or an oven etc) through which you can peep	a small hole (usually round and finished around the edges) in cloth or leather for the passage of a cord or hook or bar
	a hole (in a door or an oven etc) through which you can peep