I saw this movie in a theater in the mid-1960s — probably between 1964 and 1968. It was in color. It was a science fiction/horror movie and the main character was a young man who looked human but at some point in the movie one side of his face got torn off and you could see electronics beneath. I think the young man was an astronaut, but I’m not sure. My older brother thinks the young man was supposed to be a Frankenstein-like character.
There was also a large dinosaur like monster in the movie.