c. 1300, "something seen in the imagination or in the supernatural," from Anglo-French visioun, Old French vision "presence, sight; view, look, appearance; dream, supernatural sight" (12c.), from Latin visionem (nominative visio) "act of seeing, sight, thing seen," noun of action from past participle stem of videre "to see."
This is from the productive PIE root *weid- "to know, to see" (cognates: Sanskrit veda "I know;" Avestan vaeda "I know;" Greek oida, Doric woida "I know," idein "to see;" Old Irish fis "vision," find "white," i.e. "clearly seen," fiuss "knowledge;" Welsh gwyn, Gaulish vindos, Breton gwenn "white;" Gothic, Old Swedish, Old English witan "to know;" Gothic weitan "to see;" English wise, German wissen "to know;" Lithuanian vysti "to see;" Bulgarian vidya "I see;" Polish widzieć "to see," wiedzieć "to know;" Russian videt' "to see," vest' "news," Old Russian vedat' "to know").
The meaning "sense of sight" is first recorded late 15c. Meaning "statesman-like foresight, political sagacity" is attested from 1926.
