I can "see" them but can't visualize them. It's like I know what they look like but if I closed my eyes and trying to visualize the Mona Lisa on a wall I'd just see the variations of darkness that are there.

Interestingly enough, doing ketamine therapy can induce visuals but it's like bad AI where I can see flickers and flashes of things but nothing like, say, the penguin scene in Fight Club.