I've commented elsewhere about an 4D maze (https://urticator.net/maze/ https://urticator.net/maze/ - I am not the author) which mimics this by creating two 3D r

I've commented elsewhere about an 4D maze (https://urticator.net/maze/ https://urticator.net/maze/ - I am not the author) which mimics this by creating two 3D retinas in red/blue stereoscopic mode - when you cross your eyes just right you see a single volumetric 3D retina.