If you wear glasses I suggest trying both with and without your glasses on while moving your head. For me, there is almost no effect without my glasses on. But with glasses, it is quite strong... but I'm not even sure if what I'm seeing when I have my glasses on is actually the intended effect. I've become used to that effect with blue and red light moving in opposite directions relative to each other when I move my head.

Weirdly I'm the opposite; red looks closer to me with my glasses off, but both colors appear about the same with them on.

-3.5 here, the illusion is both effective with or without glasses

+1 makes red pop out very strongly for me. Without glasses only very slightly.

I see the red rings in front. I tried adding some depth cues to see if I could see it both ways - https://i.imgur.com/LsPtsRr.png

It kind of works, but for me it feels more like the blue ring now has a variable depth, with parts below and parts above the red rings, kind of like a piece of fabric draped over a bar.

I wonder how it feels for people who see blue in front?

I see the red rings in the front, but if I close one eye, they look flat. That was confusing, but the paper explains it nicely.

first few seconds : nothing special, just flat

then: blue ring appeared "closer" to me (very similar to a stereogram - yes)

I was able to "force" the blue ring to snap to being "behind" the red rings by rapidly blinking but the effect wouldnt stick .... the perception would slowly snap back to my default - blue in the front

That one, for me, is sorta like the ballerina thing, in that with a small mental effort I can make it switch between the two states. But honestly my first glance at it, they look largely "flush" - not a super strong 3d effect in either direction.

Even with effort I couldn't make them not appear 'flush' and I'm beginning to question my sanity

I've noticed the same effect with stained glass, that blue tends to recede for me and red comes forward.

I spend a lot more time in churches, especially ones with stained glass, than most people, but I hadn't thought to ask if it happens to other people too.

That's a very cool illusion. First time I see it. I wonder if the color patterns on the different rings have something to do with it.

From the Kitaoka's paper:

http://www.psy.ritsumei.ac.jp/~akitaoka/Kitaoka2015_Referenc...

> More specifically, a closer object projects to a more temporal part in the retina and so does red light. This suggestion, however, made Bruecke immediately reject his hypothesis because some of his observers reported red receding with respect to blue.

> The Stiles-Crawford effect is a phenomenon that the rays entering the eye through the peripheral regions of the pupil are less efficient than those through the central region [24]. This two-factor model, which Vos [4] called the “generalized Bruecke-Einthoven explanation,” has been widely accepted, while a few authors did not approve it [25]. Many studies suggested that pupil size affects chromostereopsis [19, 21–23], which supports the generalized Bruecke-Einthoven explanation. Simonet and Campbell [26], however, did not find any consistent relationship between pupil size and chromostereopsis.

Maybe the explanation is not 100% physiological in nature.

https://arxiv.org/abs/2208.03726

Human Perception as a Phenomenon of Quantization – Diederik Aerts, Jonito Aerts Arguëlles – 2022

> For two decades, the formalism of quantum mechanics has been successfully used to describe human decision processes, situations of heuristic reasoning, and the contextuality of concepts and their combinations. The phenomenon of 'categorical perception' has put us on track to find a possible deeper cause of the presence of this quantum structure in human cognition. Thus, we show that in an archetype of human perception consisting of the reconciliation of a bottom up stimulus with a top down cognitive expectation pattern, there arises the typical warping of categorical perception, where groups of stimuli clump together to form quanta, which move away from each other and lead to a discretization of a dimension. The individual concepts, which are these quanta, can be modeled by a quantum prototype theory with the square of the absolute value of a corresponding Schrödinger wave function as the fuzzy prototype structure, and the superposition of two such wave functions accounts for the interference pattern that occurs when these concepts are combined. Using a simple quantum measurement model, we analyze this archetype of human perception, provide an overview of the experimental evidence base for categorical perception with the phenomenon of warping leading to quantization, and illustrate our analyses with two examples worked out in detail.

> in this article, we would like to pay attention to visual perception that takes place in this more primitive first-line phase and quantum structures that would be present there. A specific situation in visual perception, namely, the bi-stability that occurs when viewing figures drawn on a two-dimensional background that we nevertheless visually reconstruct into ‘seeing three dimensional entities’, of which the ‘Necker cube’ is the archetypal example, was studied within the quantum cognition approach. The presence of quantum structure was investigated and convincingly demonstrated (Conte at al., 2009; Atmanspacher & Filk, 2010).