I have amblyopia—also known as lazy eye—which means I often see a bit of double vision—usually a sliver duplicated on the outside side of one of my eyes, even when I’m wearing contacts, and even though I don’t look like I have a lazy eye. My eyes definitely don’t work in concert and I’m told my 3D vision resembles what people see when they look at a postcard.
Finally, when I use binoculars, I use only one eyehole up to the non-lazy eye… So I’m wondering what exactly you normal people see out of binoculars? Is it like Looney Tunes?
Until you get them adjusted, you can get this kind of view (sort of), especially when you first pick them up and are bringing them to your eyes.
Once situated correctly (with the rubber eye cups touching your face so the lenses are the same distance away), your brain merges the images just like wearing glasses.
You can get this effect if the binoculars haven’t been adjusted to match your pupillary distance (how far apart your pupils are).