I haven't noticed persisting visuals, but I feel like crap the day after taking 2C-I. I end up feeling worn out mentally and physically. I've taken it twice, and it will be a long time before I take it again. My life responsibilities are too demanding right now.
I find if i take it in the morning/get a good bit of sleep then I feel great. If I take it at night/don't get much sleep I feel pretty crappy.