Dispersion Of White Light By A Glass Prism What happens when light falls on the surface of a compact disc (CD) or a prism? We see that when light falls on a CD or. a prism, it splits up into its many colours. The process of splitting up of white light into many colours is called dispersion.The band of colours produced when white light is split up is called a spectrum. A … [Read more...] about Dispersion Of White Light By A Glass Prism