Wow! So a visual effect similar to some psychadelic hallucinations is associated with brain cleaning!

Also, I've been at concerts where the light show guy seems to have reverse-engineered the filters our brains use to process raw signal into "images", and could use the lights to create just the raw primitives.

A few hours of that and it was like I was learning to see all over again, a tune-up/calibration of my visual system.