Light Bloom 2D GLSL filter

Does anyone know where I can find custom 2D filters for GLSL? I searched the sight but came up with very few helpful results (probably my fault, not yours).
Specifically, I’m looking for light bloom and a way to change screen brightness, for pupil dilation after coming out of a subway tunnel. Certainly there’s something like this already out there, I’m just looking for a re-direct. Thanks!

Pupil dilation:
Download the .blend. It is enabled by defaults there.