Witches' Eye is a uncommon Artifact — Equipment card from Theros (THS), collector number 222. Current market price: $0.15 (foil $0.35), TCGplayer market prices via Scryfall.
Equipped creature has "{1}, {T}: Scry 1." (To scry 1, look at the top card of your library, then you may put that card on the bottom.) Equip {1}