The Eye of Horus
The ancient Egyptian Eye of Horus or wedjat ("Whole One") is a powerful symbol of
protection, and it is also considered to confer wisdom, health and prosperity. Horus was one of the most important Egyptian gods,
a sun-god represented as a falcon or with the head of a hawk, whose right eye was the sun and whose left eye was the moon.
He was the son of Osiris (god of the underworld) and Isis (the mother goddess). Osiris was slain by his own brother, the evil Set
(jackal-headed god of night), and Horus fought Set to avenge his father's death, winning the battle but losing an eye in the
process. The eye was restored by the magic of the god of wisdom and the moon, Thoth, and this allowed Horus to grant Osiris
rebirth in the underworld. The Eye of Horus symbol was used in funerary rites and decoration, as instructed in the Egyptian
Book of the Dead.
After 1200 BC, the Eye of Horus was used to represent fractions, based on repeated division by two. Each part of the Eye was
assigned a fractional value (as shown right), and combinations of parts were drawn to represent fractions. So, for example, the
pupil and the brow together are equivalent to 1/4 + 1/8 = 3/8.
As can be seen from the Egyptian tablet on the left, both the right and the left eyes of Horus were depicted by the ancient
Egyptians. The wounding of the left eye served as a mythical explanation of the phases of the moon, and its magical restoration
meant that the left was usually the one used as an amulet and considered to be the "Eye of Horus." The right eye is
sometimes referred to as the "Eye of Ra," the sun god, though often little distinction is made between the two eyes.
A depiction of Horus as falcon-god of the sun is shown in our discussion of the Ogdoad.
Variations of the Eye of Horus are often encountered, a notable case being the all-seeing eye in the Great Seal of the United States.
The reverse of the Great Seal is shown below, followed by a detail of the Eye symbol that completes the pyramid.