In Snow World, patients can use a computer mouse to maneuver around and interact with (e.g. by throwing snowballs at snowmen, penguins, and wooly mammoths) a snow covered virtual environment while listening to music. Display devices that can be used to display virtual environments used in distraction interventions can range in complexity and cost from fully immersive environments such as Snow World displayed in a wide field of view, high-resolution head-mounted display on the high end, to desktop computers using inexpensive polarized or shutter glasses in combination with stereoscopic projectors or large 3-D monitors.”