Can anyone explain the optics of double vision?

Can anyone explain the optics of double vision?

I find it hard to understand, how and why do i see two clear images?
Is it some kind of reflection?


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There are different opinions. My best guess is that it optically comes from a small cylinder error, which the brain tries to fix by sharpening the image with some sort of deconvolution filter. The double vision would then be an artifact of this sharpening.

This would be consistent with the double vision many people with astigmatism see, and how it disappears when adding a lens that corrects for that.

At least my double vision totally behaves like that. I get the most double vision exactly on the most myopic meridian of the eye that has more cylinder error.


If you think about it, the back of the eye is curved. That means all the receptors are not at the same plane like a piece of film or digital sensor (curved film planes and sensors notwithstanding). If you throw the image slightly out of focus, some areas are getting higher light intensity than others. Wouldn’t this cause the image to appear to break up?

We also don’t know if the receptors act in groups (binning) as far as the image processing.