The Nazar Bonjuk was born of the age-old "evil eye" superstition that one person can cast a spell on another. To prevent this, Anatolian artisans (3000 B.C.) have created blue glass "eyes" that "look" straight back at the spell-caster as if to say "I see what you're doing, and you can't get away with it!"
The Nazar bonjuk is an object which you believe has magic powers to protect you or bring good luck. It has no religious significance, and few people really believe in the evil eye superstition anymore. But it's an enjoyable tradition.