Blue light is a common form of light that is emitted from a range of natural and artificial sources. The phenomenon is all around us, permitted by the sun and by our digital devices, tablets, smartphones, TVs, computers and even some energy-efficient lighting. Sunlight, for example, contains many shades of red, orange, yellow, green and blue light rays, which vary depending on the energy and wavelength of the individual rays. When combined together, the spectrum of coloured light rays creates a phenomenon known as ‘white light’, which we refer to as sunlight.