In El Salvador there is a belief in the evil eye or mal ojo. When giving it to someone it can cause harm. Babies are more susceptible to getting sick from the evil eye. The mal ojo goes hand-in-hand with “vista fuerte” or strong sight. If you have a string sight you can cause harm to others especially babies. This is why everyone is required to hold the baby, in order no to accidently kill it with the negative energy. Babies are also protected with a red string. (See a different part of this under evil eye)
My informant is a building engineer. He migrated to the United States form El Salvador when he was 16 years old. He grew up in a city in El Salvador. Lots of the folklore he has heard has come from his family.
This is interesting because the evil eye can either be used as protection or to cause harm. The various ways that the evil eye is used is truly remarkable