No, it’s not a rave toy gone horribly wrong, it’s another spooky tool making its way into the hands of law enforcement and the military. Designed as one of a growing body of non-lethal incapacitating devices, the flashlight uses ultra bright, rapidly pulsating LEDs to first temporarily blind and then induce nausea and sometimes vomiting. The pulses quickly change color and duration, which can cause psychophysical effects in many people (although to what extent varies significantly). The same effect is sometimes inadvertently seen by helicopter pilots when sunlight rapidly flashes through their rotors, disorienting them in mid-flight. The flashlight has obvious downsides—the victim must be in front of the light and must not think quickly enough to look away—but is a promising tool for non-violent enforcement.