Prisoner's cinema is a phenomenon reported by people kept in darkness for long periods of time. From darkness, faint hues begin to appear, shapeless forms that slowly group themselves together, becoming more and more distinguishable from the void. Scientists refer to these light shapes as phospohenes, from the Greek words phos (light) and phainein (to show). Phosphenes, characterized by the experience of seeing light despite no actual light entering the eye, can be directly induced by stimulation of the retina or visual cortex as well as by the random firing of cells in the visual system. It is also a common precursor to falling asleep.

The shapes of phosophenes can vary widely, but certain forms are reported more often than others. Many people report seeing an elliptical shape, or a series of elliptical shapes, reminiscent of the human pupil itself. The shape is often marked by a small protrusion similar to that found on the shape of the Mandelbrot set of complex numbers 'c' for which the sequence (c, c ≤ + c, (c ≤ + c) ≤ +c, ((c ≤ +c) ≤ +c)) + c, . . . ) does not approach infinity.

Still Image, Night Before the Morning Sun

When visualized, the Mandelbrot set (named after the Polish born mathematician who studied and popularized it) is a fractal, exhibiting a repeating pattern that can be seen at at every scale of magnification. The set's boundary incorporates smaller versions of the main shape, so the fractal property of self-similarity applies to the entire set, and not just to its parts.

Fractals, and indeed the Mandelbrot set itself, are observed in various scales, throughout the natural world.