MIT’s Technology Review looks at — but not directly into — the Department of Homeland Security’s new Incapacitating Flashlight:
The flashlight, which is being developed for the Department of Homeland Security (DHS), uses a range finder to measure the distance to the target’s eyes so that it can adjust the energy of the light to a level that won’t cause permanent damage. Then it rapidly shoots out pulses of light from an array of ultrabright light emitting diodes (LEDs).The flashes incapacitate a person in two different ways, says Robert Lieberman, CEO of Intelligent Optical Systems, based in Torrance, CA, which is making the device. The flashes temporarily blind a person, as any bright light would, and the light pulses, which quickly change both in color and duration, also cause what Lieberman calls psychophysical effects. These effects, whose effectiveness depends on the person, range from disorientation to vertigo to nausea, and they wear off in a few minutes.
It’s not clear why the changing light pulses cause this effect, even though the effect has been well documented, Lieberman says. Helicopter pilots, for example, have been known to crash because they get disoriented by the choppy flashes of sunlight coming through the chopper’s spinning blades.