When dealing with black magic, there are often signs you look out for as an indication as to whether you are being affected. Where the signs for possession of jinn are easy to spot, signs for evil eye are a lot harder as there are no definitive signs and the symptoms may vary in some cases.
The Prophet (صلى الله عليه و سلم) said after destiny ( al-qadar ) my Ummah will die mostly due to Evil Eye.
Evil Eye (Nazar) takes Man to the graveyard and Camel to the Pot.
Evil Eye makes one fall down from the mountain.
Evil Eye can either be caught by someone who had no intention of giving you it or it can be sent by a magician to cause you harm.