37 7.6 DAZZLING WEAPONS UTILITY AND DESIGN 7.6.1 Dazzling weapons are a form of directed energy weapon that use, for example, lasers or light-emitting diodes (LEDs) to achieve their effects. In law enforcement operations, they are used especially against subjects in a moving vehicle. Depending on the model, they can be used to engage targets at distances of up to several kilometres. CIRCUMSTANCES OF POTENTIALLY LAWFUL USE 7.6.2 Dazzling weapons may be useful in high-risk scenarios, such as in counterterrorism operations, in particular as an alternative to the use of firearms. Given that there are, however, other potentially safer alternative means of stopping a vehicle, dazzling weapons should be used only in exceptional circumstances. In order to ensure that these weapons do not cause blindness, their safety controls should include a mechanism, such as a rangefinder or automatic cut-off, or they should use lower-power light sources. SPECIFIC RISKS 7.6.3 Dazzling weapons may reversibly impair the functioning of the retina or even cause permanent blindness.112 When used against drivers, the outcome may be that the vehicle being driven is crashed. There may also be particular risks of photosensitive epileptic seizures as a result of strobe lighting. Light scattering by a laser beam, caused by dirt or imperfections in a vehicle’s windscreen, may obscure the driver’s vision and increase the risk of crashing, even if the driver’s eyes are not directly targeted by the beam. See for example International Commission on Non-Ionizing Radiation Protection (ICNIRP), “Guidelines on Limits of Exposure to Laser Radiation of Wavelengths between 180 nm and 1,000 μm”, Health Physics, vol. 105, No. 3 (2013), pp. 271–95. 112