I've noticed that if I stare at something or, better yet, at a pattern for a bit of time, it will start to move, similar to what you see after staring at those swirly spiral gifs, but less intense. As the description I found says, it is the same as motion aftereffects in the way, that it looks like it's moving, but at the same time, when you look closely, it looks as if the position it's moved to is where it was supposed to be.
I'm 16, not on any medication.