Glow in the dark things were not invented because you can't invent something that was already existing! Someone did discover it though: Hennig Brand. He was a German scientist (we would call him a scientist- in those days, he was called an alchemist) and he found the substance phosphors, which all glow in the dark things contain. Brand saw that the phosphors, which reacts to a great extent, glowed when it was combined with oxygen ("glow" in the dark). This is the substance that causes glow in the dark items like clothing, toys and bracelets to glow!!

The original glow in the dark was made from a toxic material called Radium. My Uncle Takeishi Osaka of Tokyo Japan invented the modern version of glow in the dark. You oldsters may remember that glow in the dark once only came in that off green sort of color. He also invented a way of ionizing that allowed pigment to stick to the chemical allowing the various colors we now have. Uncle Takeishi died in the late 1980's. He dedicated his life to helping the blind and this was one of his achievements in that area.