If what you see through your left eye alone is further to the left, then it is also further to the rear.
What am I talking about?
UPDATE 8 August 2011: What I’m talking about is stereoscopic 3D. Look at something on the screen (pause the disc, it helps) through the 3D glasses. Spot something that looks further to the back, that’s behind something that looks closer to the front. Close your left and right eyes in turn, and you’ll soon see that the item further to the back also appears further to the left through your left eye than the item closer to the front.
Which makes sense, because that’s how stereoscopic vision works in the real world as well.