Robert M. Huff studied the health practices of many societies and wrote a book Promoting Health in Multicultural Populations: A Handbook for Practitioners(1999).
According to Huff , Evil Eye is an old and fairly widespread superstition found in the Mediterranean and Aegean areas as well as among Hispanic population groups in the United States, Mexico, Central, and South America. It goes by many names including mal occhia in Italy, ayin harsha in Arabic cultures, and mal de ojo in Hispanic cultures. It is also known as bad eye, narrow eye, the look, and the wounding eye. A person with this power can cause another person harm merely by looking at them. This belief is felt in some cultures to be tied directly to the heart, and a person with the evil eye is often covetous or jealous of something that belongs to another. It is believed that anyone can have this power, though it is often ascribed more to elderly women. The possessor of the evil eye may not be aware that he or she possesses it, and any harm that is inflicted is usually unintentional. For those who use it intentionally, the evil eye is linked to witchcraft, sorcery, and black magic.
Among Hispanic cultures, mal de ojo is a folk illness caused by evil eye that can cause a child’s blood to heat up and can lead to a variety of physical problems, including diarrhea, upset stomach, fever, vomiting, and inconsolable crying. Treatment requires the services of a traditional health practitioner, who may use prayer or other approaches to resolve the illness. Evil eye can be counteracted using a variety of methods and devices, including amulets worn around the neck and certain magical practices and prayers. As with black magic, belief in the evil eye is a problem that is sometimes encountered by modern health practitioners. In such instances the practitioner needs to recognize the patient’s beliefs, and possibly include elements of traditional remedies along with modern medical approaches to treat the symptoms. Often, however, belief in such powers can keep people from seeking needed medical attention.