All perfect praise be to Allaah, the Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and messenger.
In a Prophetic narration on the authority of Ibn ‘Abbaas the Prophet, sallallaahu ‘alayhi wa sallam, mentioned that the effect of the evil-eye is real and that if something could ever precede the predestination, it would have been the effect of the evil eye. Moreover, he, sallallaahu ‘alayhi wa sallam, ordered the person who has affected another person with evil-eye to take a bath and give the water he washed up with and give it to the affected person if the latter asks him to do so. [Muslim]
For a Muslim to protect himself from envy, he should recite the legislated Ruqyah on himself.
For more benefit on Ruqyah and the treatment of envy, please refer to Fataawa 89017 and 85883, and to Fatwa 88933 on the conditions for Ruqyah, and to Fatwa 86605 on the symptoms which show that a person is envied.
Allaah Knows best.