Ayin Hara actually literally means, the eye of an evil one. Other-wise, in order for the expression to mean evil eye, it would lingusitically have to be ayin hara-ah, as ayin is loshon nekaiva. Just saying. An eye is not evil, but the evil person who has bad intentions towards someone, just might have enough zechyos (hard as that might be to believe), to have his tefilos for evil answered by Hashem. And if the person towards whom he directs his evil thoughts is possibly lacking in some area, it just might be enough to tip the scales against him.
This is one reason why tefila b’tzibur is better than yichidus. Collectively ALL our merits might tip the scales in someone’s favor for his bakashos, even if he alone does not deserve it.