object glass vs objective lens

object glass and objective lens both are nouns.

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

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

object glass 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 glass include object lens, objective.

object glass (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