Brief description
When wearing the Iron Man suit, Tony Stark can see information about his surroundings displayed on the visor, so it is superimposed over what his human vision shows him. For instance, in his first combat scene wearing the suit designed in his workshop at home, he faces a group of soldiers who are pointing guns at hostages. On his visor, he can see enemies' faces marked in red and hostages' faces marked in green, and when he fires his weapons, they only kill the enemies, leaving the civilians free.