The Tibetan Buddhist esoteric practice of a dark retreat, in which experienced practitioners with guidance from a teacher remove all light stimuli for 49 days, has long been shrouded in secrecy. The practice is a simulation of the bardo, the transitional consciousness state at the time of dying. Esteemed Tibetan medical practitioner and teacher Dr. Nida Chenagtsang has become an advocate for selectively bringing this practice to the fore as part of his healing practice.