It has to do with binocular parallax and ocular dominance. Binocular parallax is the phenomenon whereby an object appears different in you left eye than it does in your right eye. This makes sense, since your eyes are physically in two different places.
Ocular dominance is the tendency for your brain to prefer information from one eye over the other. There's a test to determine which of your eyes is dominant. With both eyes open, point at an object a couple of meters away. Now look at where you're pointing with one eye, then the other. The eye through which your finger is more closely aligned with the object is your dominant eye.

This awesome diagram represents an artist looking at a rectangle (B) on his inclined work surface. Due to binocular parallax and perspective, his right eye looks at B and sees A (skewed right), and his left eye looks at B and sees C (skewed left).
Because I'm left eye dominant, I'll draw A and think it looks like B (since that eye's left-skewing tendency "corrects" the right-skewed rectangle). Conversely, someone who is right eye dominant will draw C and think it looks like B.
What do you think? Does my theory hold water? It seems to explain why I always skew things to the right. Test this shit out yourself and tell me if it works!
















