An Etymological Dictionary of Astronomy and Astrophysics

The act or power of sensing with the eyes. → averted vision; → acuity of vision.

Etymology (EN): M.E., from O.Fr. vision, from L. visionem (nominative visio) “act of seeing, sight, thing seen,” from p.p. stem of videre “to see,” cognate with Pers. bin, present stem of didan “to see”
(Mid.Pers. wyn-; O.Pers. vain- “to see;” Av. vaēn- “to see;”
cf. Skt. veda “I know;” Gk. oida “I know,” idein “to see;” PIE base *weid- “to know, to see”).

Etymology (PE): Negâh, “look,” from Mid.Pers. nikâh “look, glance, observation;” Proto-Iranian *ni-kas- “to look down,” from ni- “down, below,” → ni- (PIE),

• *kas- “to look, appear;” cf. Av. nikā-, nikāta- (in the name of the 15-th nask) “that which is observed,” ākas- “to look;” Mid.Pers. âkâh, Mod.Pers. âgâh “aware, knowing;” Skt. kāś- “to become visible, appear;” Ossetic kast/kaesyn “to look;” did, from didan “to see” (Mid.Pers. ditan “to see, regard, catch sight of, contemplate, experience;” O.Pers. dī- “to see;” Av. dā(y)- “to see,” didāti “sees;” cf. Skt. dhī- “to perceive, think, ponder; thought, reflection, meditation,” dādhye; Gk. dedorka “have seen”).