Why do some toys glow in the dark? It’s not magic. This happens because of phosphor, a chemical commonly used in such products. This substance radiates light after being energised. These glow-in-the-dark toys and objects need to be exposed to light, or charged. The light works on the phosphors and excites their electrons. Then, there is light! What happens is that the electrons release extra energy and produce the light. Zinc sulphide and strontium aluminate are two phosphors most commonly used in such glow-in-the-dark products.