When I was about 15, living in my parents home, I awoke in the middle of the night and noticed a fluorescent yellow/green light emanating from below the horizon of my bed.

I slowly lifted my head to locate the source of the light.  (My bed was about 25"-30" tall) upon lifting my head I could immediately make out a circular, smooth glowing surface no less than 12" from my bedside.   I kept lifting my head and body to reveal more of it.  
Next which came into view was the points of 2 diagonally set, polished, obsidian-like, Large eyes.  It did not move.  It however was emanating a yellow green glow which initially caught my attention.  (Something I am yet to hear elsewhere in reports)  
I lifted my head just enough to see half of the eyes and remember the book/movie, Communion, and immediately recognized it as the grays they sleek of.  
I immediately panicked and covered me head and 'played dead' for what seemed  like hours, till I eventually drifted off to sleep.  
I have considered this to be hypnagogic hallucinations but the sheer terror, I felt with adrenaline pumping.  I would have certainly been awake.  It was absolutely not a dream.  It was there.