Movie from the 1960's where mad scientist or wizard/warlock keeps people in cage in his underground lair and blinds them with some type of laser or light beam. This could have been a foreign "sword and sandals" movie, like Sampson or Hercules. I also remember an army of ghosts on horseback that could kill live soldiers but could not be hurt themselves. Arrows would pass right through them because...well, they're ghosts! Any idea what movie this was from? It's possible I'm mixing up two different movies.
I saw the movie when I was a kid at Saturday Matinee in my home-town theater in the early 1970's. The matinee was always some Hammer horror film or Italian dubbed Hercules type film. Definitely not Dark Crystal or a Lou Farigno movie.