The Eye of Horus, or Wadjet, takes its stylized form from a real anatomical layering: a human eye and eyebrow combined with two facial markings borrowed from a falcon, since Horus was represented as a falcon or as falcon-headed. Egyptologists including Richard Wilkinson read the individual strokes of the classic form as later folded into a fraction notation used in medical and grain-measure texts, each part of the eye assigned a unit fraction of a hekat measure, though whether this fraction scheme reflects the symbol's original design intention or a secondary, playful mathematical use layered onto an existing image is not settled from the surviving sources.
The symbol appears across an unusually wide range of media for a single Egyptian religious sign: painted on coffins and funerary equipment, carved as amulets in stone, faience and metal, and painted on the bows of boats, where its protective sense extended from the body of the dead to the vessel carrying the living. Amulet examples survive in a wide range of materials, faience, carnelian, gold and glazed steatite among them, spanning production from the Old Kingdom through the Ptolemaic period, a continuity of manufacture across roughly two and a half thousand years that few other Egyptian amulet forms match.