About 2D vision.

My opinion is that this is the same uneven canon as Murdoc's green skin and the fate of Cyborg Noodle.

In some interviews, due to poor eyesight, he literally met with a hanger, and in others he easily plays instruments, comments on people's hairstyles and movies, as well as rides cars, motorcycles and roller skates.

My personal headcanon is that the 2D level depends on when he last hit his head, and also because of the constant migraine.