anopia vs sightlessness

anopia and sightlessness both are nouns.

Word	Noun	Adjective	Verb	Adverb
anopia	Yes	No	No	No
sightlessness	Yes	No	No	No

As nouns, sightlessness is a hypernym of anopia; that is, sightlessness is a word with a broader meaning than anopia:

anopia: sightlessness (especially because of a structural defect in or the absence of an eye)
sightlessness: the state of being blind or lacking sight

Other hypernyms of anopia include blindness, cecity.

anopia (noun)	sightlessness (noun)
sightlessness (especially because of a structural defect in or the absence of an eye)	the state of being blind or lacking sight