The Dark retreat (Wylie: mun mtshams) is used to cultivate higher-level spiritual practices in Taoism and Tibetan Buddhism (Dzogchen lineages from the Tibetan Nyingma and Bön traditions). It is an individual retreat in solitude and complete darkness, where there is no light vibration of any kind that could affect the eye of a person in seclusion.
Since there is no external optical stimulation to the physical level of the body, a person can perceive the manifestation of internal lights (which is an extended and not authentic form is sometimes called “prisoner’s cinema” in Western culture). The length of the dark rite varies in different traditions from a few hours to decades. In the Himalayan tradition, it could only be completed under the guidance of an expert high spiritual master.
The experience of practices completed in the dark is considered valuable for coping with the post-death intermediate state (bardo) on a mental level and for skillfully managing one’s consciousness at the moment of death. Also, the experiences gained in the dark are necessary for achieving one of the highest realizations (the rainbow body – the dissolution of the body into the five basic elements on the level of light).
For followers of the Buddhist tradition, before entering the retreat, their spiritual master gives clear instructions about which mental exercises and breathing techniques to perform in the dark and what to pay attention to and later evaluates the student’s performance.
The Men Ling House of Dark retreat is used by most practitioners of the Yuthok Nyingtik lineage of spiritual teachings of Tibetan Medicine around the world, having been instructed by the Tibetan physician and teacher, Dr. From Nida Chenagtsang or other authorized lineage holders of the same authentic ancient teaching.