UK bans powerful laser pointersBMJ 1997; 315 doi: https://doi.org/10.1136/bmj.315.7118.1251e (Published 15 November 1997) Cite this as: BMJ 1997;315:1251
The British government has banned the most powerful laser pointers because they could cause retinal damage if shone directly into the eye. The pens are used as presentation aids, but they have also been misused to distract goalkeepers, policemen, and drivers at night.
Dr Ajoy Kar, reader in physics at Herriot-Watt University in Edinburgh, used sophisticated calibrated laser power meters to show that the beam from one of the more powerful laser pointers is a hundred times more intense than the brightest sunlight. Following Dr Kar's research, all class 3 laser devices have been banned, although the weaker class 1 and 2 devices are still available.
The classification of these devices differs in the United States and Europe. Under the European classification products up to class 3A are safe. In the United States a 5 mW laser device—the power often used in laser key chains—is a class 3A product, whereas in Europe, according to the International Electrotechnical Committee's classification, they are class 3B, a more stringent classification. For a 5 mW device to cause permanent retinal damage, the exposure time can be as little as two seconds.
Since their introduction as teaching aids, laser devices have become more readily available. Apart from being used by nightclubbers and concert goers, they have been used to impede the vision of drivers at night. A teenager has become the first person to be convicted of assault with a laser pen—for shining the beam into a police officer's eyes. There have also been reports that children have been competing with each other to see who can tolerate staring at the laser beam the longest.
Dr Kar said: “I was asked to carry out tests on these devices by the government. Class 1 and 2 lasers are safe, and the eye is protected by the blink reflex, but 5 mW lasers are potentially dangerous and should not be looked at directly.”