Flicker

Flicker is rapid fluctuation in a light source’s output, usually inherited from how the LED driver converts AC mains to DC current. Deep flicker at low frequencies causes headaches and eye strain over a shift; around rotating machinery it can create a stroboscopic effect where a spinning chuck appears slowed or stopped — a genuine safety hazard in workshops. It is quantified by percent flicker and flicker index, with IEEE 1789 giving recommended limits by frequency. Quality LED drivers with good output filtering reduce ripple to a few percent, effectively imperceptible. When specifying industrial lighting, ask for the driver’s ripple or flicker data rather than assuming — two fixtures with identical lumens can behave very differently on a factory floor.