Devices that temporarily blind people can now be used by US police, but are they worth the risks?
THE US police and coastguard may soon start using laser "dazzlers" like those the American and British militaries have employed for years at checkpoints in Iraq and Afghanistan.
At the SHOT Show last month in Las Vegas, Nevada, B.E. Meyers Electro-Optics of Redmond, Washington, unveiled the first laser dazzler that has been approved for non-military law enforcement by the US Food and Drug Administration. Though they are purportedly less harmful than other non-lethal weapons, such as tasers and rubber bullets, the International Committee of the Red Cross is concerned that not enough has been done to lessen the risk of people suffering permanent blindness.
Dazzlers are designed to warn people away by temporarily blinding them with pulses of green laser light. Unlike tasers or rubber bullets, there is no possibility that the lasers could kill a person, they just create a beam that is too intense to look at.
Most models that have been built for military use are designed to work at distances of 300 to 500 metres during the day and a kilometre or so at night. This makes them attractive for long-range use at sea to stop vessels suspected of drug trafficking, for example. At 40 metres, however, the intense beam of a 200-milliwatt laser can permanently damage eyes. Despite this, they have seen regular use in Iraq since 2006.
"We have had some injuries," says a former researcher at the US army's Brooke Army Medical Center in San Antonio, Texas, who asked not to be named, "but for the most part they have been minor." That is partly because, when faced with a bright light, people instinctively look away. Also, the pupil of the eye contracts in a tenth of a second, quickly reducing the amount of light reaching the retina.
Not all injuries are minor, however. The researcher recounted the story of a soldier he interviewed after an incident in Iraq a few years ago. While on duty, the soldier fumbled a dazzler he was trying to point at an oncoming vehicle a safe distance away. "He was in an awkward position and illuminated a rearview mirror in such a way that he got a beam directly back into the eye." The beam had gone less than 6 metres when it hit the soldier in the centre of vision of his right eye, burning the retina and leaving his vision in that eye permanently damaged...