In some forms, it is the belief that some people can bestow a curse on victims by the malevolent gaze of their magical eye. The most common form, however, attributes the cause to envy, with the envious person casting the evil eye doing so unintentionally. Also the effects on victims vary. Some cultures report afflictions with bad luck; others believe the evil eye may cause disease, wasting, or even death. In most cultures, the primary victims are thought to be babies and young children, because they are so often praised and commented upon by strangers or by childless women. The late UC Berkeley professor of folklore Alan Dundes has explored the beliefs of many cultures and found a commonality—that the evil caused by the gaze is specifically connected to symptoms of drying, desiccation, withering, and dehydration, that its cure is related to moistness, and that the immunity from the evil eye that fish have in some cultures is related to the fact that they are always wet. His essay "Wet and Dry: The Evil Eye" is a standard text on the subject.
In many beliefs, a person—otherwise not malefic in any way—can harm adults, children, livestock or possessions, simply by looking at them with envy. The word "evil" is somewhat misleading in this context, because it suggests an intentional "curse" on the victim. A better understanding of the term "evil eye" can be gained from the old English word for casting the evil eye, namely "overlooking", implying that the gaze has remained focused on the coveted object, person, or animal for too long.
The amount of literary and archeological evidence attests to the belief in the evil eye in the eastern Mediterranean for millennia starting with Hesiod, Callimachus, Plato, Diodorus Siculus, Theocritus, Plutarch, Heliodorus, Pliny the Elder, and Aulus Gellius. In Peter Walcot'sEnvy and the Greeks (1978) he referenced more than one hundred of these authors' works related to the evil eye. Studying these written sources in order to write on the evil eye only gives a fragmented view of the subject whether it presents a folkloric, theological, classical, or anthropological approach to the evil eye. While these different approaches tend to reference similar sources each presents a different yet similar usage of the evil eye, that the fear of the evil eye is based on the belief that certain people have eyes whose glance has the power to injure or even kill and that it can be intentional or unintentional.
The classical evil eye
Belief in the evil eye during antiquity is based on the evidence in ancient sources like Aristophanes, Athenaeus, Plutarch, and Heliodorus. There are also speculations that claim Socrates possessed the evil eye and that his disciples and admirers were fascinated by Socrates' insistently glaring eyes. His followers were called Blepedaimones, which translates into "demon look," not because they were possessors and transmitters of the evil eye, but because they were suspected of being under the hypnotic and dangerous spell of Socrates.
In the Greco-Roman period a scientific explanation of the evil eye was common. Plutarch's scientific explanation stated that the eyes were the chief, if not sole, source of the deadly rays that were supposed to spring up like poisoned darts from the inner recesses of a person possessing the evil eye (Quaest.Conv. 5.7.2-3=Mor.80F-81f). Plutarch treated the phenomenon of the evil eye as something seemingly inexplicable that is a source of wonder and cause of incredulity.
The belief in the evil eye during antiquity varied from different regions and periods. The evil eye was not feared with equal intensity in every corner of the Roman Empire. There were places in which people felt more conscious of the danger of the evil eye. In the Roman days not only were individuals considered to possess the power of the evil eye but whole tribes, especially those of Pontus and Scythia, were believed to be transmitters of the evil eye.
The spreading in the belief of the evil eye towards the east is believed to have been propagated by the Empire of Alexander the Great, which spread this and other Greek ideas across his empire.