object lens vs objective lens

object lens and objective lens both are nouns.

Word	Noun	Adjective	Verb	Adverb
object lens	Yes	No	No	No
objective lens	Yes	No	No	No

As nouns, object lens and objective lens are synonyms defined as:

object lens and objective lens: the lens or system of lenses in a telescope or microscope that is nearest the object being viewed

Other synonyms of object lens include object glass, objective.

object lens (noun)	objective lens (noun)
the lens or system of lenses in a telescope or microscope that is nearest the object being viewed	the lens or system of lenses in a telescope or microscope that is nearest the object being viewed