A real eye opener. Not for me, had one in the eye doc chair - sight blacked out for a short while (reason I went to eye doc). Had one about 2 weeks earlier. Left eye blinked out for a few minutes. Had the window shade thing that got my carotid cleaned about a yr earlier. Yup concussion is strange. Got rear-ended by an F450 pulling a long trailer. Couldn't read the guy license plate. Went away OK but whiplash made me go see the Chirodoc. Wake up in the morning, no doc apts today, FINE day.