Blue light is a colour in the visible light spectrum. It has a shorter wavelength and contains more energy than other colours. We get natural doses of blue light from the sun but also increasingly high exposures from computers screens, televisions, tablets and smart phones. The use of these devices late into the night and subsequent exposure to blue light (beyond the natural cycle of the sun) is known to confuse our circadian rhythm and disrupt our sleep cycle. If you struggle with sleep, minimising your exposure to artificial blue light sources in the hours before bed can be extremely helpful.