Member Rara Avis
I get floaters in my eyes all the time.
I also see the pulsing edge-color of things when I get horrendous migraines.
One floater scared me big time -- it was like a gray, spheroid sponge that revolved and twisted at the edge of my line of sight.
And, yes, brian, the ants marching IS the heartbeat. Can you make blood rush through your ears? I can. Neat trick (internally, anyway).
And I've seen a ghost. Or, *something* anyway, suddenly tapping on the windows in the middle of a strange, dense fog. Perhaps a prank?