The Eye of Wdjat is an Ancient Egyptian symbol, appearing various times throughout Yu-Gi-Oh! media. In Egyptian mythology, Wdjat was the protector of Lower Egypt, and the eye symbol used by her was slightly altered to create the Eye of Horus and later the Eye of Ra.
A modified version, called the Eye of Anubis or Millennium Symbol also appears throughout the series.
The Millennium Puzzle is the only Millennium Item that has the entire Eye of Wdjat on it, instead of just the Eye of Anubis.