"extent," 1530s, "room to act," from Italian scopo "aim, purpose, object, thing aimed at, mark, target," from Latin scopus, from Greek skopos "aim, target, object of attention; watcher, one who watches" from metathesized form of PIE *spek-yo-, suffixed form of root *spek- "to observe." Sense of "distance the mind can reach, extent of view" first recorded c. 1600.
"instrument for viewing," 1872, abstracted from telescope, microscope, etc., from Greek skopein "to look" (from PIE root *spek- "to observe"). Earlier used as a shortening of horoscope (c. 1600).
"to view," 1807, from the source of scope (n.2). Related: Scoped; scoping.