There is an aforism which says that medicine today is so advanced nobody’s healthy any longer. I used to half-jokingly paraphrase this to the effect that there was no body organ of mine that was entirely all right. More specifically I used to say that except for colour-blindness there wasn’t a sight deficiency I didn’t suffer from. Short-sightedness, long-sightedness, strabismus, astigmatism, take your pick.
What I never mentioned though was my suspision I didn’t see three-dimensionally. The earliest example was a time in the primary when a schoolmate brought one of those photographs you had to look upon with one red and one green glass to see, 3D, a man and a woman doing it in a shower. It was a disappointment not because I was gay but because even with those glasses on I still just saw two pictures printed one over the other, only the hues were different. Later indication was inability to thread a needle, no matter how near to or far from my eyes, unless I turned it a bit to get a second reference, so to say. And so on.
I never mentioned this because I never heard such condition existed and I had another suspision, namely, that I was just pretending something and in fact the real condition in this particular case was hypochondria. So I was paradoxically relieved the other day when I found out it really existed. And once I knew its name it was easy to find some tests, like this one, to ascertain it was really what was the matter with me.
Short as the ‘pedia article was, it also explained to me why I did see 3D when watching something move, for example. (Have you ever tried to slowly ‘fly’ over the Highlands in Google Earth at eye level some 2km? It’s smashing.) Apparently the problem is not about the idea of 3D yourself, your brain can handle that – it’s just that your dominant eye is so dominant that it only lets the other eye broaden your field of view (and take over when the dominant one is shut), but not adjust the information the dominant eye gets itself.
By the way, I recently also found out that something unrelated I had never noticed at anybody (obviously not at myself) but had been told by a few people I was doing, that is, gritting my teeth in sleep instead of snoring, exists as well.