Two British authors & trainers in the core shamanism field, Ross Heaven & Simon Buxton, used to run a workshop called “Darkness Visible” in which participants wore Mindfolds (these things) for several days, and they also released a book about it, there’s some previewed on Google Books here.
This is from the Amazon page for that book:
The first book to examine the spiritual and therapeutic practice of retreat in physical darkness to explore inner light
• Shows how experiencing complete darkness over prolonged periods helps in developing mental clarity and creativity
• Draws upon many indigenous and spiritual traditions that use this technique
The use of ceremonial darkness is a classic and cross-cultural method for exploring hidden aspects of unconscious and super-conscious states, accessing invisible landscapes, and embracing the deeper recesses of the self. In Darkness Visible Heaven and Buxton examine the spiritual and therapeutic practice of taking retreat in physical darkness.
For millennia mystics and sages have used darkness as a spiritual tool for breaking with their pasts, prior conditioning, and the limited reality of their societies. Spiritual seekers from many traditions–Celtic, Eastern, indigenous North and South American, Tibetan, and African–have used darkness as a tool for spiritual enlightenment. Heaven and Buxton show how experiencing complete darkness, even for only a period of hours, brings about a remarkable clarity and mental stillness and thus provides a springboard for creativity, intuition, and spiritual development. They include exercises that explore lucid levels of dream consciousness, drawing both from their experience as teachers of this method and from the many cultures that include this practice in their spiritual traditions. Darkness Visible shows how deprivation of sight can truly teach us to see.
I didn’t attend the workshop, but met a few people who did, and a lot of them were newish to trance journeying and visualisation and said it helped them.
I have a Mindfold (they’re worth the money btw, because they don’t press onto your eyes) and am intending to do some kind of 12- or 24-hour darkness meditation soonish, probably oriented around Saturn, using that. I was thinking of maybe the first Saturday after the summer solstice, 28th June, as the world turns back towards darkness, but I haven’t completely decided yet.
That’s all I have on the topic of using visual input to control internal perceptions… if/when I do the darkness work, fates willing I’ll post it on the forum.