Darkness therapy, also known as terapie tmou in the Czech Republic, is a form of therapy that involves spending extended periods of time in complete darkness. It is based on the concept of restricted environmental stimulation therapy (REST), which includes both flotation REST, which involves floating in a sensory deprivation tank, and chamber REST, which involves lying in a dark, quiet room for 24-48 hours. Practitioners of darkness therapy believe it can have a range of benefits, including preventing "lifestyle diseases" such as cancer and metabolic disorders, improving creativity and sharpening the senses, and "regenerating the psyche." However, there is limited scientific evidence to support these claims. Some research has suggested that REST can have certain psychological and physiological benefits, such as improved mood and reduced stress, but further research is needed to fully understand the effects of darkness therapy. Some researchers have questioned the effectiveness of darkness therapy, with one chronobiologist stating that there is no evidence that blind people produce more melatonin than sighted people, and that any increase in melatonin production in darkness therapy may not have significant health benefits. Others have raised concerns about the lack of scientific evidence and potential risks associated with the therapy, including the possibility of inducing anxiety or psychological distress.
The article and its sources do not appear to understand that darkness retreats, in which the entire body is immersed in complete darkness, cannot be accurately compared to the experience of being blind: Blind people are normally also exposed to light, and will have no darkroom effect, unless in a darkness retreat (bardo retreat/yang-ti retreat).
However, despite being full of various misconceptions, the article mentions that many practitioners of darkness therapy, also known as terapie tmou, point to a 49-day Tibetan retreat called yang-ti as its most important forebear. It is not clear from the text how similar these two practices are, as the article does not provide any further information about yang-ti or how it compares to darkness therapy. However, it is worth noting that Tibetan Buddhism does have a tradition of retreats called "bardo retreats," which involve prolonged periods of meditation in seclusion. These retreats are typically held in monasteries or isolated retreat centers, and involve a strict schedule of meditation and other spiritual practices, with the goal of achieving insight and enlightenment.
https://www.theatlantic.com/health/archive/2018/07/darkness-therapy-czech-republic/564365/
