The evil eye (nazar dosh) is a human look believed to cause harm to someone or something else. The supernatural harm may come in the form of anything from a minor misfortune to disease, injury or even death. The evil eye is essentially a specific type of curse, and has its roots in magical thinking and superstition. Any bad event for which there was not an obvious cause might be blamed on a curse.
Scientifically, each and every living being is associated with a set of ELF (Extremely Low Frequency) electromagnetic Signals emitting from them. So, your brain waves certainly interact with the brain waves of others around you. If a person is looking at you with ill-intentions, he/she certainly has those uncomfortable waves emitting from him/her, which are unpleasant to you and your body, and as a result, you may fall sick, or any other such thing.