Dark retreat (Wylie: mun mtshams) refers to advanced practices in the Taoism, Dzogchen lineages of the Nyingmapa, Bönpo, other schools of Tibetan Buddhism. A dark retreat is a solo retreat in a space that is completely absent of light. Because there is no optical stimulation, one can experience “prisoner’s cinema”, commonly known as the lights. The time period dedicated to dark retreat varies from a few hours to decades. Dark retreat in the Himalayan tradition is a restricted practice only to be engaged by the senior spiritual practitioner under appropriate spiritual guidance. This practice is considered conducive for navigating the bardo at the time of death and for realising the rainbow body. The traditional dark retreat requires stability in the natural state and is only suitable for advanced practitioners. Ayu Khandro and Dilgo Khyentse are examples of modern, if not contemporary, practitioners of significant periods of Dark retreat sadhana.
History
Some spiritual traditions have used similar techniques in the pursuit of enlightenment: Kogi people spend 9 years in dark caves or huts in Colombia, in Europe, the dark room appeared as a network of tunnels, in Egypt as the Pyramides, in Rome as the catacombs, by the Essenes in Israel and Taoists in China as caves. Ancient Greeks practiced the oracular discipline of enkoimesis or incubatio.
Czech Television reporter, Silvie Dymáková (winner of the main prize for documentary filmmaking in the Czech Republic “Czech Lion award”), documented a week in dark retreat.
Ayu Khandro performed the Yang-Ti (Tibetan), an advanced practice of the Dzogchen Upadesha, a version of the Dark Retreat.