Ian McCollum of Forgotten Weapons has just released his latest video, in which he examines the firearms used in the original Star Wars movie, released in 1977. They were based on real firearms, but embellished with add-on components and props to look more like science fiction weapons.
I found the presence of an OEG (occluded eye gunsight) particularly interesting, because this was originally developed in South Africa (a few years after Star Wars came out). I used one of the first models to be produced there, and found it intriguing. Basically, one doesn't look through the sight at all: it's a solid object that can't be seen through. One keeps both eyes open, so that with one eye one sees the target, and with the other the red dot image in the otherwise blank sight. One's brain superimposes the dot on the target, making it relatively easy to hit what one's aiming at.
I must admit, though, I prefer today's red dot sights, where I can see the target through the sight.