Horus is the Eye of Ra or the Eye of Horus known as the "all seeing eye" and is believed the right eye of horus is the sun and the left eye of horus is the moon.
"Eye of Horus
The Eye of Horus was one of the most common amulets of ancient Egypt. This highly stylized eye of the falcon-head, solar and sky god Horus (the Latin version of Hor) is associated with regeneration, health, and prosperity. Also is has become associated with the esoteric and the occult. Another name for the eye is udjat or utchat, meaning "sound eye."
Horus, the son of Osiris and Isis, was called "Horus who rules with two eyes." His right eye was white representing the sun while his left eye was black representing the moon. According to Egyptian legend Horus lost his left eye during a fight with his murderous uncle, Seth, to revenged his father's death. Seth tore out his nephew's eye but lost the fight because the assembly of the gods declared Horus the victor. The eye was reassembled by the magic of Thoth. Then Horus gave the eye to Osiris who experienced rebirth in the underworld.
As an amulet the Eye of Horus has three versions: a left eye, a right eye, and two eyes. The eye is constructed in fractional parts, with 1/64 missing, a piece that Thoth added with magic. The Eye of Horus is depicted as a human eye embellished with a typical Egyptian cosmetic extension and subtended by the markings of a falcon's cheek. The symbol of modern pharmacies and prescriptions, Rx, is derived from the three pieces of the Eye of Horus.
In ancient Egypt the eye was used as a funeral amulet as protection against evil and rebirth in the underworld, and for decorating mummies, coffins, and tombs. The Book of the Dead instructs that funerary eye amulets be made out of lapis lazuli or a stone called mak; some were gold-plated.
When worn as jewelry fashioned of gold, silver, lapis, wood, porcelain, or carnelian the eye served to ensure safety, protect health, and provide the wearer with wisdom and prosperity; it was called the "all-seeing Eye." Other attributes associated with it are terror and wrath; some myths tell that the eye seems to assume a personality of its own, swooping down from the sky to right wrongs. The latter attributes appear to come from the legend that after the eye was torn out by Seth, it was restored by Isis, and thence symbolized security of kingship, perfection and protection against the evil influence of Seth. A.G.H.
Horus was an ancient a sky god whose eyes were said to be the sun and the moon. However, he soon became strongly associated with the sun (and the sun god Ra as Ra-Horakhty ("Ra, who is Horus of the two horizons") while Thoth was associated with the moon. An ancient myth describes a battle between Horus and Set in which Horus´ right eye was torn out and Set lost his testicles! Thoth magically restored Horus´ eye, at which point it was given the name "Wadjet" ("whole" or "healthy"). In this myth it is specifically stated that it is Horus´ left eye which has been torn out, so the myth relates to the waxing and waning of the moon during which the moon appears to have been torn out of the sky before being restored once every lunar month.
There are a number of depictions of the restoration of the eye in Greco-Roman temples. Thoth is assisted by fourteen gods including the gods of the Ennead of Hermopolis or thirty male deities (in Ismant el-Kharab, the Dakhla Oasis). Each god represented one of the fifteen days leading up to the full moon, and to the waning moon. The restored eye became emblematic of the re-establishment of order from chaos, thus closely associating it with the idea of Ma´at. In one myth Horus made a gift of the eye to Osiris to help him rule the netherworld. Osiris ate the eye and was restored to life. As a result, it became a symbol of life and resurrection. Offerings are sometimes called "the Eye of Horus" because it was thought that the goods offered became divine when presented to a god.
The Eye of Horus was believed to have healing and protective power, and it was used as a protective amulet. It was also used as a notation of measurement, particularly for measuring the ingredients in medicines and pigments. The symbol was divided into six parts, representing the shattering of Horus´ eye into six pieces. Each piece was associated with one of the six senses and a specific fraction.
More complex fractions were created by adding the symbols together. It is interesting to note that if the pieces are added together the total is 63/64 not 1. Some suggest that the remaining 1/64 represents the magic used by Thoth to restore the eye, while others consider that the missing piece represented the fact that perfection was not possible. However, it is equally likely that they appreciated the simplicity of the system which allowed them to deal with common fractions quickly, after all they already had a symbol for the number "1" and they had other numerical notations available when they needed to use smaller fractions."