hawk-eyed vs keen-sighted

hawk-eyed and keen-sighted both are adjectives.

Word	Noun	Adjective	Verb	Adverb
hawk-eyed	No	Yes	No	No
keen-sighted	No	Yes	No	No

As adjectives, hawk-eyed and keen-sighted are synonyms defined as:

Other synonyms of hawk-eyed include argus-eyed, lynx-eyed, quick-sighted, sharp-eyed, sharp-sighted.

hawk-eyed (adjective)	keen-sighted (adjective)
having very keen vision	capable of seeing to a great distance
	having very keen vision