tiredness vs asthenopia

tiredness and asthenopia both are nouns.

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

As nouns, asthenopia is a hyponym of tiredness; that is, asthenopia is a word with a more specific, narrower meaning than tiredness:

tiredness: temporary loss of strength and energy resulting from hard physical or mental work
asthenopia: a tiredness of the eyes caused by prolonged close work by a person with an uncorrected vision problem

Other hyponyms of tiredness include eyestrain, jet lag, exhaustion, grogginess, logginess, loginess, senioritis.

tiredness (noun)	asthenopia (noun)
temporary loss of strength and energy resulting from hard physical or mental work	a tiredness of the eyes caused by prolonged close work by a person with an uncorrected vision problem