How do you make a screen slightly glitch when you are close to a certain humanoid?

I'm making a horror game which mostly revolves around being chased around long hallways and key progression.

Recently, I've thought of a character idea that can technically bend reality at it's own. Me and the other people i'm working with have decided that it'd be cool if the screen glitched when you get close to him, but we aren't sure how to make it.

Any help?