weariness vs eyestrain

weariness and eyestrain both are nouns.

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

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

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

Other hyponyms of weariness include asthenopia, jet lag, exhaustion, grogginess, logginess, loginess, senioritis.

weariness (noun)	eyestrain (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