An example of evil eye is intense jealousy or envy towards a person such that this gets converted into physical harm. Of course, there is no such thing as evil eye, but Islam teaches you how to protect yourself from it.
The following hadith talks about how a man Sahl who had beautiful skin, and Amir praised him by saying he had skin like a virgin, and then Sahl fell down unconscious. When they told the Prophet, he reprimanded Amir for what he did to Sahl.
Yahya related to me from Malik that Muhammad ibn Abi Umama ibn Sahl ibn Hunayf heard his father say, “My father, Sahl ibn Hunayf did a ghusl at al-Kharrar. He removed the jubbah he had on while Amir ibn Rabia was watching, and Sahl was a man with beautiful white skin. Amir said to him, ‘I have never seen anything like what I have seen today, not even the skin of a virgin.’ Sahl fell ill on the spot, and his condition grew worse. Somebody went to the Messenger of Allah, may Allah bless him and grant him peace, and told him that Sahl was ill, and could not go with him. The Messenger of Allah, may Allah bless him and grant him peace, came to him, and Sahl told him what had happened with Amir. The Messenger of Allah, may Allah bless him and grant him peace, said, ‘Why does one of you kill his brother? Why did you not say, “May Allah bless you?” (ta baraka-llah) The evil eye is true. Do wudu from it.’ Amir did wudu from it and Sahl went with the Messenger of Allah, may Allah bless him and grant him peace, and there was nothing wrong with him.”
وَاتَّبَعُوا مَا تَتْلُو الشَّيَاطِينُ عَلَىٰ مُلْكِ سُلَيْمَانَ ۖ وَمَا كَفَرَ سُلَيْمَانُ وَلَٰكِنَّ الشَّيَاطِينَ كَفَرُوا يُعَلِّمُونَ النَّاسَ السِّحْرَ وَمَا أُنزِلَ عَلَى الْمَلَكَيْنِ بِبَابِلَ هَارُوتَ وَمَارُوتَ ۚ وَمَا يُعَلِّمَانِ مِنْ أَحَدٍ حَتَّىٰ يَقُولَا إِنَّمَا نَحْنُ فِتْنَةٌ فَلَا تَكْفُرْ ۖ فَيَتَعَلَّمُونَ مِنْهُمَا مَا يُفَرِّقُونَ بِهِ بَيْنَ الْمَرْءِ وَزَوْجِهِ ۚ وَمَا هُم بِضَارِّينَ بِهِ مِنْ أَحَدٍ إِلَّا بِإِذْنِ اللَّهِ ۚ وَيَتَعَلَّمُونَ مَا يَضُرُّهُمْ وَلَا يَنفَعُهُمْ ۚ وَلَقَدْ عَلِمُوا لَمَنِ اشْتَرَاهُ مَا لَهُ فِي الْآخِرَةِ مِنْ خَلَاقٍ ۚ وَلَبِئْسَ مَا شَرَوْا بِهِ أَنفُسَهُمْ ۚ لَوْ كَانُوا يَعْلَمُونَ
And they followed [instead] what the devils had recited during the reign of Solomon. It was not Solomon who disbelieved, but the devils disbelieved, teaching people magic and that which was revealed to the two angels at Babylon, Harut and Marut. But the two angels do not teach anyone unless they say, “We are a trial, so do not disbelieve [by practicing magic].” And [yet] they learn from them that by which they cause separation between a man and his wife. But they do not harm anyone through it except by permission of Allah . And the people learn what harms them and does not benefit them. But the Children of Israel certainly knew that whoever purchased the magic would not have in the Hereafter any share. And wretched is that for which they sold themselves, if they only knew.
بِسْمِ اللَّهِ الرَّحْمَٰنِ الرَّحِيمِIn the name of Allah, the Entirely Merciful, the Especially Merciful.١ قُلْ أَعُوذُ بِرَبِّ الْفَلَقِ1 Say, “I seek refuge in the Lord of daybreak٢ مِنْ شَرِّ مَا خَلَقَ2 From the evil of that which He created٣ وَمِنْ شَرِّ غَاسِقٍ إِذَا وَقَبَ3 And from the evil of darkness when it settles٤ وَمِنْ شَرِّ النَّفَّاثَاتِ فِي الْعُقَدِ4 And from the evil of the blowers in knots
٥ وَمِنْ شَرِّ حَاسِدٍ إِذَا حَسَدَ5 And from the evil of an envier when he envies. (Quran Surah Falaq, 113)
Abu Sa’id Al-Khudri (May Allah be pleased with him) reported:
The Messenger of Allah (ﷺ) used to seek protection against the evil of jinn and the evil eyes till Surat Al-Falaq and Surat An-Nas were revealed. After they were revealed, he took to them for seeking Allah’s protection and left everything besides them. (At- Tirmidhi).
Magic was worked on Allah’s Messenger (ﷺ) so that he began to imagine that he had done something although he had not. One day while he was with me, he invoked Allah and invoked for a long period and then said, “O `Aisha! Do you know that Allah has instructed me regarding the matter I asked Him about?” I asked, “What is that, O Allah’s Messenger (ﷺ)?” He said, “Two men came to me; one of them sat near my head and the other sat near my feet. One of them asked his companion, ‘What is the disease of this man?’ The other replied, ‘He is under the effect of magic.’ The first one asked, ‘Who has worked magic on him?” The other replied, ‘Labid bin A’sam, a Jew from the tribe of Bani Zuraiq.’ The (first one asked), ‘With what has it been done?’ The other replied, ‘With a a comb and the hair stuck to it and a skin of the pollen of a male datepalm tree.’ The first one asked, ‘Where is it?’ The other replied, ‘In the well of Dharwan.’ Then the Prophet (ﷺ) went along with some of his companions to that well and looked at that and there were date palms near to it. Then he returned to me and said, ‘By Allah the water of that well was (red) like the infusion of Henna leaves and its date-palms were like the heads of devils” I said, O Allah’s Messenger (ﷺ)! Did you take those materials out of the pollen skin?” He said, ‘No! As for me Allah has healed me and cured me and I was afraid that (by Showing that to the people) I would spread evil among them when he ordered that the well be filled up with earth, and it was filled up with earth ” (Bukhari)
‘Aishah (May Allah be pleased with her) reported:
The Messenger of Allah (ﷺ) said, “Angels were created from light, jinns were created from a smokeless flame of fire, and ‘Adam was created from that which you have been told (i.e., sounding clay like the clay of pottery). (Muslim)
And We have certainly beautified the nearest heaven with stars and have made [from] them what is thrown at the devils and have prepared for them the punishment of the Blaze. (Quran 67:5)
And He completed them as seven heavens within two days and inspired in each heaven its command. And We adorned the nearest heaven with lamps and as protection. That is the determination of the Exalted in Might, the Knowing. (Quran 41:12)
I heard Allah’s Messenger (ﷺ) saying, “The angels descend, the clouds and mention this or that matter decreed in the Heaven. The devils listen stealthily to such a matter, come down to inspire the soothsayers with it, and the latter would add to it one-hundred lies of their own.” (Bukhari)It was narrated from Abu Hurairah that:The Prophet said: “When Allah decrees a matter in heaven, the angels beat their wings in submission to his decree (with a sound) like a chain beating a rock. Then “When fear is banished from their hearts, they say: ‘What is it that your Lord has said?’ They say: ‘The truth. And He is The Most High, The Most Great.” He said: ‘Then the eavesdroppers (from among the jinn) listen out for that, one above the other, so (one of them) hears the words and passes it on to the one beneath him. The Shihab (shooting star) may strike him before he can pass it on to the one beneath him and the latter can pass it on to the soothsayer or sorcerer, or it may not strike him until he has passed it on. And he ads one hundred lies to it, and only that word which was overheard from the heavens is true.” (Ibn Majah)
It seems Muhammad thought that Allah was above in the sky and the devils were astronauts flying in space! (See Islam’s Geocentric View of the Universe post)
And what do these creatures eat for dinner, you might ask? Well, toilet paper and poop! Bones actually, which was 7th century toilet paper.
Allah’s Messenger said: “Do not perform Istinja (cleaning yourself after urinating or defecating), with dung, nor with bones. For indeed it is provisions for your brothers among the Jinn. (Tirmidhi)
These creatures, do they have religions? Why yes, they are Muslims, Jewish, Hindu, Buddhist jinns too!
Regarding the explanation of the Verse: ‘Those whom they call upon (worship) (like Jesus the Son of Mary, angels etc.) desire (for themselves) means of access to their Lord (Allah) as to which of them should be the nearer and they hope for His Mercy and fear His torment.’ (17.57) They themselves (e.g. Angels, saints, Apostles, Jesus, etc.,) worshipped Allah, Those Jinns who were worshipped by some Arabs became Muslims (embraced Islam), but those human beings stuck to their (old) religion. Al- A`mash said extra: ‘Say, (O Muhammad): Call unto those besides Him whom you assume (to be gods).’ (17.56) (Bukhari)