asthenopia vs eyestrain

asthenopia and eyestrain both are nouns.

Word	Noun	Adjective	Verb	Adverb
asthenopia	Yes	No	No	No
eyestrain	Yes	No	No	No

As nouns, asthenopia and eyestrain are synonyms defined as:

asthenopia and eyestrain: a tiredness of the eyes caused by prolonged close work by a person with an uncorrected vision problem

asthenopia (noun)	eyestrain (noun)
a tiredness of the eyes caused by prolonged close work by a person with an uncorrected vision problem	a tiredness of the eyes caused by prolonged close work by a person with an uncorrected vision problem