Glow in the dark products work because of a chemical additive which allows the product to absorb energy on one frequency, and reemit it as visible light which is a different frequency. Zinc sulphide and strontium aluminate are the most commonly used phosphors for photoluminescent products as they reemit energy over a considerably long period. When light is shone upon a glow in the dark object, incoming photons excite the phosphor molecules and these molecules then release that energy taken in by releasing photons and creating a dim light glow. Different phosphors release energy at different rates and thus, the slower a phosphor releases energy, the longer it will glow. The human eye is most sensitive to green light in the dark which is why night vision technology was traditionally created with a green tint