how can they see anything?

That's what I was thinking, watching an old western on our little black and white TV back in the early 50s. I was sitting alone in our living room, listening to the cloppity cloppity sounds of horses hooves, cowboys circling round and round a little house somewhere out in the old west. Almost pitch black, I could just make out some silhouettes of the riders charging by, their guns a blazing! How could they see anything?