Do not go into the Light.....

the blue cast in this image is the colour of the tube lights that make it impossible for intravenous drug users to find a vein. The efficacy of these lights for that purpose has been questioned, with some suggesting that drug users simply find a vein outside the zone of fluorescence and mark the spot with a marker for accessibility when inside the zone of fluorescence. There is currently no published evidence supporting the idea of a deterrent effect.