Need help with a post-process material

Hello everyone!
I’m developing a survival horror game, with the player playing through the view of a handheld camera.
I need a post process effect that makes it look like the lens of the camera broke. (in case of damage or death).
I know that I could simply put a texture of a broken glass on screen but I need something more realistic. (Refraction and distortion to simulate the broken glass).

The problem is that I have 0 clue of how to achieve this, somebody got an idea?
It doesn’t have to be a post-process material, any idea is greatly appreciated, thank you!