The so called "Evil Eye" is a classic example of syncretic beliefs.
It goes by a couple name, but for example in Turkey it is usually known as Nazar. It is simply a symbol, usually a concentric pattern of circles in blue and white, that is supposed to ward off evil spirits.
In Turkey, it the most visible sign of many Animistic beliefs. The use of this symbol is actually fundamentally incompatible with Islam, but the two beliefs are widely practiced side by side and people are generally unaware of the conflict of interest they pose each other. The symbol is so universal in Turkey that it is almost impossible to avoid. Even as a Christian with no interest in having them around, I am constantly founding the things floating around my house. They are printed on receipts, dropped as tokens into shopping bags and boxes, woven into clothing, left as tokens by wary guests, and generally come out of the woodwork like dust bunnies.
In addition to being incompatible with Islam, belief in the Evil Eye to ward off evil spirits is incompatible with Christianity. If some of our trust for safety is placed in something other than Christ, that thing becomes an idol that detracts from our focus on our Savior. The one who is able to protect us from all evil Spirits is the one who Himself triumphed over them:
Colossians 2:15 (ESV) He disarmed the rulers and authorities and put them to open shame, by triumphing over them in him.