Middle English fer, from Old English feor "to a great distance, long ago," from Proto-Germanic *ferro (source also of Old Saxon fer, Old Frisian fir, Old Norse fiarre, Old High German fer, Gothic fairra), from PIE root *per- (1), base of words for "through, forward," with extended senses such as "across, beyond" (source also of Sanskrit parah "farther, remote, ulterior," Hittite para "outside of," Greek pera "across, beyond," Latin per "through," Old Irish ire "farther"). For vowel change, see dark (adj.). Paired with wide to mean "everywhere" since 9c.
1550s, "look at, view, inspect" (a sense now obsolete), from sight (n.). From c. 1600 as "get sight of, bring into one's view;" 1842 as "take aim along the sight of a firearm." Related: Sighted; sighting.
<a href="https://www.etymonline.com/word/far-sighted">Etymology of far-sighted by etymonline</a>
Harper, D. (n.d.). Etymology of far-sighted. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/far-sighted