Strange light through my window.

I was in my bed, listening to the radio, when a beam of ultra-intense, green light, like that in a photocopier came through a space between the bottom of my curtain and the window sill. (approximately a one inch space).  The light shone on my ceiling as if the source were on the ground, then began moving across my ceiling, down the wall, then across the floor toward me. 
As the light hit me I was paralyzed. It was quite obvious that the source of the light began on the ground and was lifting upward outside my window.  It stopped as suddenly as it began and left my ears ringing. 
I was about 16 at the time, was home alone, and was terrified.  
I have researched thousands of reports over the years, but none similar to my experience.  I want to know what the hell happened to me that night!!!  I am 45 now, and lately, I've a feeling something relating to that night is being "awakened" in me.  Are they coming back? 
Somebody please talk to me!  That was 30 years ago.
Witness indicates that date of incident is approximate.  PD