As muslim we believe that the evil eye exists in this world according to the hadith of the prophet Muhammed (PBUH)
In sahih Muslim,
Abu Huraira reported so many ahadeeth from Allah's Messenger (may peace be upon him) and he reported Allah's Messenger (may peace be upon him) as saying: The influence of an evil eye is a fact.
another hadith in sahih Muslim
Ibn 'Abbas reported Allah's Messenger (may peace be upon him) as saying: 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 bath (as a cure) from the influence of an evil eye, you should take bath.
and in Bukhary,
Narrated Abu Huraira:
The Prophet said, "The effect of an evil eye is a fact." And he prohibited tattooing.
So in Islam we know it exists and it may affect muslims and non-Muslims too. So we should seek refuge by reading the Day and night athkar, or reading the 3 last surahs of the Quran(An-Nas,Al-Falaq and As-samad) after each prayer.
Narrated Uqbah ibn Amir:
The Messenger of Allah (peace_be_upon_him) commanded me to recite Mu'awwidhatan (the last two surahs of the Qur'an) after every prayer.