Allaah says (interpretation of the meaning):
“And from the evil of the envier when he envies.”
“And verily, those who disbelieve would almost make you slip with their eyes (through hatred)”
Ibn ‘Abbaas and others said, commenting on this verse (113:5) :
"this means, they put the evil eye on you with their glances."
The Prophet ﷺ said:
“The evil eye is real and if anything were to overtake the divine decree, it would be the evil eye. When you are asked to take a bath (to provide a cure) from the influence of the evil eye, you should take a bath.”
“The evil eye is true”
“Seek refuge with Allaah from the Evil eye because certainly it is true.”
“The influence of an evil eye is a fact; if anything would precede the destiny it would be the influence of an evil eye, and when you are asked to take a bath (as a cure) from the influence of an evil eye, you should take bath.”
Imaam al-Nawawi رحمه الله said in Sharh Saheeh Muslim:
“In this Hadeeth (the last one quoted above) there is proof of the existence of al-Qadr and it also authenticates the fact that the harm from the evil-eye is powerful.”
Ibn al-Qayyim رحمه الله said:
“It is an arrow, shot by the one who is jealous or (or is known) for giving evil-eye towards the one who is envied – hitting (the target) sometimes and missing it sometimes. So if it is encountered while uncovered and without protection, then the person is affected by it. But no doubt, if it is encountered while taking precaution, then it will not affect him; rather it may happen that this arrow (evil-eye) is returned back to the owner himself (i.e. the owner is affected by his own evil-eye)”. [Zaad al-Ma`aad (4/154)]
The Quran, Sunnah & reality confirms that and it (evil eye) cannot be denied.