In the Arab Muslim world, the blue eye is a symbol of evil – undoubtedly left over from the old rivalry between the Byzantines and the Normans. And so the power and colour of this eye are used to ward off adversity and misfortune: in Turkey, Armenia, Iran and Greece, you can see them hanging above entranceways, on the walls in houses, on babies' clothing, attached to rear-view mirrors in vehicles, on horses and as key rings.