It is said to keep You and your children away from evil eye (buri nazar).
It also keeps away people from evil spirit or unwanted tantra mantra done.
Lord Shiva is also called ‘Neelkanth‘. According to the religious scriptures, during churning of the milky ocean, the poison or ‘Halahal’ also came out of the ocean which terrified the Gods and Demons. It was so toxic that it might have destroyed all of creation. … Lord Shiva therefore became ‘Neelkanth‘