this is hypnagogia. cool isn't it? it's basically sleep onset (stage one sleep). some researchers argue however that covert REM sleep is the cause of the visions in stage one. in any case, it's a great time to be lucid. but as you said, it's different. you can feel your body, and may still feel awake mentally but you are seeing visions with your eyes closed. some people wake up and have hypnagogic hallucinations (HH) with their eyes open. HH is often linked with sleep paralysis but can come on its own. it's closer to trance than dreams, and is the state of mind that Carl Jung worked with in his "active imagination." today, the shamanic dreamworker Robert Moss teaches how to use this state of mind for journeys.

I've written more about it at length here: Hypnagogia and Hypnopompia | dream studies portal