Dream yoga is one of the six yogas of Naropa. It begins with lucid dreaming — recognizing the dream while it is happening — and proceeds to deliberate transformation of the dream, recognition that its ephemerality is the ephemerality of all experience, and finally recognition of mind’s nature beyond the waking/dreaming distinction.
The premise is direct: the mind that dreams and the mind that wakes are the same mind. If one can become lucid in dream, one can become lucid, differently, in waking.