It is well understood that UV-B and UV-A radiation can damage DNA and proteins, leading to accelerated skin ageing. More and more attention is being paid to the contribution visible light makes to skin ageing. The most deleterious fraction of visible light is so-called “high energy visible light” (HEV) or blue light, flanking the UV spectrum.   Although most blue light is contained in daylight, typical artificial emitters of blue light are lamps and the screens of laptops, tablets ...