What is the eye of horus?

The Eye of Horus personified in the goddess Wadjet. Also it is known as The Eye of Ra or "Udjat" is an ancient Egyptian symbol of protection and royal power. The name Wadjet is derived from 'wadj' meaning 'green' hence 'the green one' and was known to the Greeks and Romans as 'uraeus' from the Egyptian 'iaret' meaning 'risen one' from the image of a cobra rising up in protection.

There are seven different hieroglyphs used to represent the eye, most commonly 'ir.t' in Egyptian, which also has the meaning 'to make or do' or 'one who does.' In Egyptian myth the eye was not the passive organ of sight but more an agent of action, protection or wrath.

In the Ancient Egyptian measurement system, the Eye Of Horus defined Old Kingdom number one (1) = 1/2 + 1/4 + 1/8 + 1/16 + 1/32 + 1/64, by throwing away 1/64 for any rational number. Eye of Horus numbers created six-term rounded-off numbers.

The 'Eye of Horus' fractions were further discussed in the Egyptian Mathematical Leather Roll following elementary definitions that built the Egyptian fraction system. Weights and measure subunits of a hekat were also connected to Eye of Horus numbers in the quotient, and as an exact remainder, the remainder including an Egyptian fraction and a ro unit, correcting the Eye of Horus 1/64 roundoff error.

So you see, it means several things.

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