Blue light is a definite hot topic these days, given the amount of time we spend glued to our screens. Though we largely receive this shortwave HEV [click here to find out what the hell that means] during the day from the sun, blue light is also emitted from the likes of smartphones, tablets and TVs. That’s all well and good, until you consider that its natural function is to keep us alert and awake. Great for concentrating at work, school or college, not so great when you’re still tossing and turning at 4am. Because lots of us sneak a quick (or not so quick) look at our phones after the lights go out at night, we end up absorbing lots of artificial blue light. This may impact things like our melatonin production, natural sleep cycle and circadian rhythm. Wait, circadian what?