At my peak it tend to get a slight 3d look on the edges of things
Like if you were wearing a pair of 3d glasses (the red and blue ones)
They also tend to flash a bit

The brighter the area, the more the effect


Also my vision shakes during this time, not really shakes, but I guess the way to explain would be like you have more than two eyeballs...

Like the small but noticable difference between one eye and both open, but with 3+ instead

That probably makes no sense..