The third kind of sleep, which is realized through sleep yoga, is clear light sleep. It is also called the sleep of clarity. It occurs when the body is sleeping but the practitioner is neither lost in darkness nor in dreams, but instead abides in pure awareness.

Clear light is defined in most texts as the unity of emptiness and clarity. It is the pure, empty awareness that is the base of the individual.

“Clear” refers to emptiness, the mother, the base, kunzhi. “Light” refers to clarity, the son, rigpa, pure innate awareness. Clear light is direct realization of the unity of rigpa and the base, of awareness and emptiness.

Ignorance is compared to a dark room in which you sleep. Awareness is a lamp in that room. No matter how long the room has been dark, the moment the lamp of awareness is lit the entire room becomes luminous.

There is a buddha in the flate, the dharmakaya. You are that luminosity. You are the clear light; it is not an object of your experience or a mental state.

When the luminous awareness in the darkness is blissful, clear, unmoving, without reference, without judgement, without center or circumference, that is rigpa. It is the nature of mind.

When thought is observed in awareness with neither grasping nor aversion, it dissolves. When the thought–the object of awareness–dissolves, the observer or subject also dissolves.