Ungratefulness: Casting evil glances brings about ingratitude within the heart. When a person is looking at so many faces and features then his own wife does not remain attractive to him. Hence, he becomes ungrateful thinking to himself that he did not get a good-looking wife. And if she is goodlooking, then he thinks to himself that she could have been more beautiful. That woman which appears more attractive to him than his own wife, then even if his own wife is beautiful, she is still not as attractive as the other woman. In this way, he is becoming ungrateful of Allah's favors. As for the one who guards his eyes out of Allah's fear, and does not look at other women, than even if his wife is not so beautiful, she is still attractive to him and in this manner he remains grateful to Allah for this favors.

Arif Billah Hazrat Maulana Hakeem Muhammed Akhtar Saheb RA

On the authority of Abu Abdurahmaan Abdullah, the son of Umar ibn Al-Khattab (ra), who said: I heard the Messenger of Allah, Muhammed (saw) say: Islam has been built on five [pillars]: testifying that there is no deity worthy of worship except Allah and that Muhammad is the Messenger of Allah, establishing the Salaah (prayer), paying the Zakah (obligatory charity), making the Hajj (pilgrimage) to the House, and fasting in Ramadan.

(Sahih Bukhari and Muslim)

We are told that if we suspect anything like sihr (witchcraft) or jinn, then Ayatul Kursi and the 3 Quls suffice from all harm and mischief.