I see in 2D (as does something like 6% of the population), and I still understand perspective just fine. In fact I have to understand perspective and general 3Dness as part of my job, and it was only after I'd been working for some 15 years that I discovered that I don't see in stereo.
Out of interest, do you mind expanding on this, please. I don't mean to be rude, but I'm more than a little curious. Do you have normal vision in both eyes? How did you discover you don't see in stereo? Do you know why you don't see in stereo?
I have normal (ish) vision in both eyes, I wear glasses to correct distance issues.
I found out in my early/mid 30's. I had a company eye test and the optometrist did a test whereby I looked into an instrument that showed a different image to each eye, in this case a bird and a cage. It should have shown as a bird superimposed in the cage, and I just
couldn't do it. He did a couple more simple tests to determine which was my master eye, and he discovered that I can swap master eye at will. I'd known that for years but didn't know the reason for it. That was it, he announced my vision was 2D.
I was born with what used to be called a "lazy eye" and had corrective surgery as an infant, but sometimes in these cases the brain never quite manages to do the stereo thing afterwards.
I've since realised a couple of things.
1) If I'd known before I took my driving test it may have disqualified me. I've since met someone with a similar problem who isn't allowed to drive. However I have a good driving record with many years no claims bonus.
2) I'd subconciously developed some small coping strategies for instances where depth perception was missing. For example when pouring from a bottle into a glass I always make sure to touch the rim of the glass with the bottle neck to ensure they're lined up, I've always done it but had never twigged as to why.
3D cinema just doesn't work at all for me, the glasses make everything darker but otherwise it's the same experience as 2D cinema, just more expensive.
