Recursion is a visual distortion which partially to completely alters the appearance of one's external environment by repeating specific sections of itself across itself in a self-similar fashion. It results in the appearance of fractal-like patterns which often zoom into or away from the original image. This effect typically occurs spontaneously and rarely sustains itself for more than several seconds. Recursion is often accompanied by other coinciding effects such as geometry and symmetrical texture repetition. It is most commonly induced under the influence of moderate dosages of psychedelic compounds, such as LSD, psilocybin, and mescaline.