Just as an aside, there are different ways to view 3D without glasses. One is the cross-eyed method. I've seen older 3D images (stereoscopes) that look like two side-by-side photos to be viewed with special lenses. However, some of these are made today for "cross-eyed viewing" where you sort of try to lose focus and regain it like looking at a stereoscope. Not exactly easy on the eyes.
This one is really odd but it works. It requires that the right eye stay fully open and the left eye squinted. After about a half minute it started to hurt.
I can't really find much about it now, but I remember in the 80s there was some technology that sort of worked on TVs. It used two cameras but then some sort of flickering between the two images to give the perception of 3D. I've found a few GIF files that show something similar. Don't look too long or you're going to get a headache.
I got it from here:
http://brainden.com/3d-pictures.htm#prettyPhoto