Display 2 Cameras at the same time 50/50 opacity?

I want to create a dizzy effect like when you drank too much alcohol so that your eyes cannot focus correctly and you see all a bit double.

I think it would work if I use 2 cameras that render at the same time and every camera renders with 50% visibility.

is that somehow possible?

There are quite a few examples of camera controllers on Unify Community. One in specific being CrossFade.