Carl Zeiss was an optician in Germany who, some people say, “influenced history from the birth of optics to cutting-edge modern technology”. Zeiss and his partner changed the world by manufacturing the first camera lenes, and those lenses are still used today– for NASA!!!
An aperture is a “hole” through which light travels, determining the cone angle in which the light rays will be captured for a photograph. Below is a picture of the mechanism (Canon 50mm f/1.8 II lens, with 5 blades)
Sloth Munchies 