There is a hole in each retina the size of nine full moons and you have never seen it, because whatever surrounds it is extended into it by construction — targets that cross it are not dimmed, they are not drawn, and the seam is shown giving way where the pattern is too fine to guess.
Drawn with: a WebGL2 shader.
Reacts to and looks like: gpu, webgl2 and audio-reactive.
Family: Visualiser.
Runs in your browser. The preview above is the same program the renderer uses.