One example of this is Egypt. The ancient Egyptian's famous eye is called "The Eye of Horus". This eye symbolizes power, health and protection. the Egyptians then attempted to copy the Eye of Horus and decorated themselves. Along with other things, this lead to the modern "Cat Eye"

The Evil eye is a common symbol between many ancient cultures. For example, some cultures that had affiliations with the evil eye are Judesim, Assyrium, Turkish, Baltic, and several other. The evil eye had the ability to infilict injury and bad fortune. So, several amulets have been created to ward of these effects. One example is the "hand charms". These charms are three-dimensional minurate flat hands. They often have a colored center. The second and final type of charm is a collection of cirulcar blue eyes with a white center. So, these are the ways the ancients protected themsleves against the evil eye.

The eye of providence was a christian symbol of God watching over humanity. This is used in several country seals and other things. It also have a similiar shape to the holy trinity. However, once it was incorperated into the U.S dollar bill, it's meaning was changed. Some people believe this symbol is now associated with the Illuminati.