Blue light is part of the visible light spectrum that can be seen by the human eye. While a particular band of the blue light spectrum – blue-turquoise light – is beneficial to our health and our sense of well-being, increasing evidence has emerged that another band of this spectrum, known as blue-violet light, is harmful to our eyes.
Light is made up of electromagnetic particles that travel in waves. These waves emit energy, ranging in length and strength. The shorter the wavelength, the higher the energy. The length of the waves is measured in nanometres (nm), with 1 nanometre equaling 1 billionth of a metre. Every wavelength is represented by a different colour, and is grouped into the following categories: gamma rays, x-rays, ultraviolet (UV) rays, visible light, infrared light, and radio waves. Together these wavelengths make up the electromagnetic spectrum.
The human eye is sensitive to only one part of this spectrum: visible light. Visible light is that part of the electromagnetic spectrum that is seen as colours: violet, indigo, blue, green, yellow, orange and red. Blue light has a very short wavelength, and so produces a higher amount of energy, which is why it is sometimes identified as ‘high energy visible’ light or HEV.
Studies prove that exposure to artificially-created blue-violet light – such as that emitted by TV screens, LED and fluorescent lights, computer monitors, and the screens of mobile phones and tablets – contributes to the death of light-sensitive cells in the retina of the human eye, which can cause serious, long-term damage to your vision, similar to the effect of age-related macular degeneration or AMD.