We read in our morning prayers, "Ha-Shem please save us from an evil friend, evil neighbor, evil tongue, evil inclination, and evil eye." Can someone really cast an "evil eye" on a fellow Jew? Why would a Merciful God allow a second party to look at what blessings an individual has received from Ha-Shem and give them the power to inflict harm or injury through an "evil eye," whatever that is?
A: To begin with, I believe that the most important thing you should know about Ayin haRa is that when, God forbid, something bad beyond our control happens to us, we should not blame it on a spiritual bad influence or search for magical antidotes. Our Rabbis in the Talmud taught us that at times of trouble we should "reflect on our own behavior" (IEFASHFESH BEMAASAV!) as the best way to learn a powerful lesson and grow from our bad experiences. That is how our Hakhamim taught us to make lemonade from a sour lemon. But, if instead of growing spiritually by facing and accepting the facts, we blame the rest of the world and attempt to identify and neutralize their "evil eyes" or other abstract powers, we are doing a disservice to our own potential spiritual growth!
As for your specific question, in Hebrew there is no such thing as an "Evil Eye." In Hebrew "eye" is feminine. If in Hebrew you wanted to talk about the concept of "Evil Eye," it would have been called "Ayin Raa" (In fact, the words Ayin Raa appear in matters of Terumah, etc., denoting "stinginess"). Ayin haRa means "the eye of the evil person," which aims to bring attention to all kinds of eventual harm that could be caused by the one who is jealous of you. "The evil person's eye" is definitely associated with envy and jealousy, and perhaps also stinginess. Why would the Almighty allow the evil person to harm us in different ways? Well, God did gave us the power to do good or evil, as part of the existential game known as "Free will."
If we want to be immune to "the evil person's eye," here are a some basic principles to follow:
* Avoid being ostentatious.
* Do not show off what you have.
* Always behave rather with modesty and austerity, for your own good, and also to avoid unnecessary envy from those who have less than us.
If you keep these simple principles, you'll be on the safest side.