I bet you could do something similar with a high-intensity digital projector behind the screen. Which could be interesting for, say, horror movies. Put togethe

I bet you could do something similar with a high-intensity digital projector behind the screen. Which could be interesting for, say, horror movies. Put together a frame with a high-contrast image, white on a black background. Maybe a mouthful of fangs, or Freddie Kruger's knives. Time it right, just before a moment where the skittish audience members will close or cover their eyes, and they'll instead see something nasty inside their eyelids.