Jim's 3D website, cont'd.

The effect of 'relaxing' your eyes can be observed if you simply look across the room and focus on a distant wall. While keeping your focus there, slowly bring one of your fingers into the field of view. Don't focus on your finger! Notice how you 'see' two fingers. Do the same but bring two fingers up. Notice how you 'see' four fingers. Now move the two fingers back and forth horizontally and 'see' notice when the two inner finger images overlap. That's what's happening for the stereo pair, the overlapped images fuse in your brain to appear 3D.