Synesthetic Photisms and Hypnagogic Visions: a Comparison

I have been a synesthete all my life and thought I understood my synesthetic perceptions rather well when, suddenly, in 2013, I began to see a new kind of internal image: hypnagogic visions. These visions, a normal state of consciousness, are known to occur somewhere between wakefulness and sleep. They appeared to me as another source of photisms, in addition to my usual synesthetic experiences. But when I described these new visions to some researchers there was a wide range of reactions, from concern, to acknowledgement of similar experiences. While hypnagogic visions are different in some ways from my synesthesia, which I previously described in my paper, Visions Shared: A Firsthand Look into Synesthesia and Art (Steen, 2001, Leonardo 34, pp. 203-208), I find they share some commonalities. In this paper I will explore both the visual similarities and differences in my synesthetic photisms and hypnagogic visions, discuss when my hypnagogic images first appeared, and where I see them. I will compare the triggers or lack of them, range of colors, lines, shapes, geometric ornamentations, and movements I see, and mention seeing usually separate synesthetic photisms and hypnagogic visions occur in the same experience.