sharpen vs refocus

sharpen and refocus both are verbs.

Word	Noun	Adjective	Verb	Adverb
sharpen	No	No	Yes	No
refocus	No	No	Yes	No

As verbs, refocus is a hyponym of sharpen; that is, refocus is a word with a more specific, narrower meaning than sharpen:

sharpen (verb)	refocus (verb)
become sharp or sharper	put again into focus or focus more sharply
make crisp or more crisp and precise	focus anew
raise the pitch of (musical notes)	focus once again
put (an image) into focus
make (one's senses) more acute
give a point to
make sharp or sharper
make (images or sounds) sharp or sharper