It took me a while to get past your statement that you and I "are strongly affected by an optical illusion," as if we were unique in the world. :-O
Actually, I believe that everyone experiences this perceptual effect. See below.
Ed
Sorry Ed, it's just that you, me and Kevin seem to agree more on this user-specific aspect on binocular use, as opposed to more scientific approaches. It would be very nice if a mathematical formula could be used to quantify this perceived property of binoculars.
However, I suppose that will not happen. I am very convinced that you are on the right track talking about size constancy, though measuring it might not be as easy as in your attached picture.
But it would be sad if this effect was put aside as mumbo-jumbo only because of its built-in inmeasurability (English is not my mother-tounge, apparently)
But besides the major difference between scientific approaches and user-perspective, I strongly suspect that the
degree or level of misperception is not equal between individuals.
AC/A ratio (accomodative convergence per accomodative power) has a lot impact on the perceived size of the retinal image. By putting prisms in front of the eyes, they will be forced to adjust their position in order to avoid double-vision. The extra-ocular muscles then send signals to the brain how their respective tension is, and the brain computes these signals with respect to the simultaneous accommodation, and finally there will be a perceived change in object size.
Anyone who goes to an optometrist can ask for a prism flipper test. Prisms with their base towards your nose will allow the eyes to converge less, and the perceived object (text) size will appear larger.
Prism with the base temporally will force the eyes to converge more than they would without them, and the perceived object size will appear smaller.
But, as I wrote, the level of change is not equal to all individuals. Some will see a small perceived size change, while others will see an immense change.
The AC/A ratio plays a certain role in this.
Thank you for sharing your knowledge, I will get back tomorrow to read even more thoroughly. Now it is 1:40 AM here and the bed cries out for me.