Blue light is a color in the visible light spectrum. It's a short wavelength with the highest energy of all visible light. The natural blue light comes from the sun; and the artificial blue light comes from digital devices, such as computers, laptops, tablets and smartphones, and it also comes from lights like LED. Blue light can reach the back of the eye and cause damage to the retina — an important component of the eye that enables vision. The eyes cannot block this harmful light by itself, that's why blue light glasses are quite important.