on the qui vive vs sharp-sightedness

on the qui vive and sharp-sightedness both are nouns.

Word	Noun	Adjective	Verb	Adverb
on the qui vive	Yes	No	No	No
sharp-sightedness	Yes	No	No	No

As nouns, on the qui vive and sharp-sightedness are synonyms defined as:

Other synonyms of on the qui vive include alertness.

on the qui vive (noun)	sharp-sightedness (noun)
lively attentiveness	lively attentiveness
	sharpness of vision; the visual ability to resolve fine detail (usually measured by a Snellen chart)