#wedjet

Egyptian sky god Horus, who has the head of a Lanner falcon and wears the double crown of a united Egypt. His right eye was the sun or morning star, representing power and quintessence, and his left eye was the moon or evening star, representing healing. Horus was associated with kingship, and pharaohs were considered his manifestation on Earth.

You could say that the never ending battle between good and evil is a real pain in the eye!

This tiny amulet represents the eye of Horus, known to Egyptologists as the wedjat eye. It is the smallest object on display in the BP exhibition Sunken cities: Egypt’s lost worlds. The wedjat eye is half human (the eye and brow), and half falcon (the vertical and spiral elements underneath). This is because it is closely associated with the god Horus, who could be shown as a falcon or falcon-headed man.

Horus was the son of Isis and Osiris. After his uncle Seth had brutally murdered his father Osiris, Horus spent his childhood hiding from his evil uncle in the marshlands of the Nile delta. When he had gained enough strength to claim his right to the throne, he confronted and defeated Seth in a battle that left one of his eyes injured. This eye was later restored by Thoth, the god of wisdom. When Horus recovered it, he offered it to his father Osiris hoping to bring him back to life. He replaced his own eye with the divine serpent, which since then served as an emblem of royalty.

Because of this, the eye of Horus was seen as a symbol of restoration, healing, sacrifice and protection. Amulets in the shape of the eye were very popular in ancient Egypt for thousands of years, from the Old Kingdom to Roman times.

See this beautiful object in the BP exhibition Sunken cities: Egypt’s lost worlds, opening 19 May 2016. 

Baboon with a wedjet eye, Ancient Egypt, 26th Dynasty (ca. 688–525 B.C.)

I noticed that quite a number of people misuse the title 'Eye of Ra' 

Original Egyptian concept of the Eye of Ra is a disc encircled by two cobras, a female counterpart of the male god Ra. It was a violent figure that subdued enemies and was depicted like this:

Eye of Ra is also a crystal, an artifact that appears in Stargate, hidden on Abydos. Also Stargate related, this is the Eye of Ra medallion from the movie found on Eart next to the chappa'ai

What you are tagging on all those pictures of amulets and tattoos is the Eye of Horus. The right eye was associated with Ra, but that didn't make it the eye of Ra. it's still just the right Eye of Horus

also this is how it was written in hieroglyphs and was called wedjet

tl;dr: Eye of Ra is a Stargate thing referencing the Eye of Horus, it's not the same thing as the ancient Egyptian Eye of Ra which was a sun disk encircled by cobras