[luketych]

Ah, that's what it's called, thanks! I read about that a while back but forgot whether it was a phenomenon of the retina or of the brain. What I am wondering is if you can use the after image as almost a skeleton for more advanced visualizations. For example, imagine the retinal after image laying down the basic shape, and then you can consciously add detail on top of that after image. Maybe using the after image as a kind of training wheels..if it's even possible..