Dream Yoga is also known as Jangwa, Gyurwa and Pelwa.
In Dzogchen, the metaphor most commonly used to describe our situation is that of a mirror and its reflections. The reflections in a mirror are like the thoughts in our mind, which if we don't recognize as being an illusory, impermanent, unmediated, manifestation of our true nature, we will react to, identify with, become conditioned by, absorbed in and embody. Our true nature state, on the other hand, is likened to the mirror itself, which underlies and embraces all of the reflections, all the while remaining pure and changeless, never being tainted or stained by any of the reflections. It is important to realize that each thought in our mind is like a dream; once we become absorbed in a thought, we have literally entered a complete dream universe and have evoked and stepped into an illusory, limited and arbitrary identity which we experience as being who we truly are. In Dzogchen, if we get immersed in our dream-like thoughts and don't recognize the pure, mirror-like nature of our mind, we are literally considered to be nonlucidly dreaming.
Buddha Shakyamuni often told his disciples to regard all phenomena as dreams. He used many examples, like an echo, a city in the clouds or a rainbow to illustrate the illusory nature of the phenomenal world. Dreams represent just one type of illusion. The whole universe arises and dissolves like a mirage. Everything about us, even the most enlightened qualities, are also dreamlike phenomena. There's nothing that is not encompassed within the dream of illusory being; so in going to sleep, you're just passing from one dream state to another.
The primary aim and foundation of dream practice is to realize during a dream that one is dreaming. Once lucidity has been established the applications are limitless.
Documented since the 8th century, Tibetan Buddhists and Bonpo were practicing a form of dream yoga held to maintain full waking consciousness while in the dream state. One important message of the book is the distinction between the Dzogchen meditation of awareness and dream yoga. The Dzogchen awareness meditation has also been referred to by the terms rigpa awareness, contemplation, and presence. Awareness during the sleep and dream states is associated with the Dzogchen practice of natural light. This practice only achieves lucid dreams as a secondary effect—in contrast to dream yoga, which aims primarily at lucid dreaming. According to Buddhist teachers, the experience of lucidity helps us understand the unreality of phenomena, which would otherwise be overwhelming during dream or the death experience.
John Hopkins....Northern New Mexico