tiredness vs eyestrain

tiredness and eyestrain both are nouns.

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

As nouns, eyestrain is a hyponym of tiredness; that is, eyestrain 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
eyestrain: a tiredness of the eyes caused by prolonged close work by a person with an uncorrected vision problem

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

tiredness (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