And don’t aim at strangers in general
Don’t aim a laser pointer towards a person’s head. This is to prevent the beam from getting in their eyes. Remember that people can move unexpectedly, so keeping away from their heads is a good idea.
Keep away from strangers
Also, don’t shine a laser on or near a stranger. This is annoying, to say the least. It can be upsetting and may create fear that a person is being targeted by a laser gunsight. This misuse creates a bad image for laser pointers.
In sports, there have been cases of “laser louts” who aim lasers at sport players in a stupid attempt to disrupt the play. It goes without saying this is unacceptable and is illegal. It is this kind of behavior that causes the public to support a ban on laser pointers.
Why lasers can cause eye damage
A laser’s light is concentrated into a narrow beam. If aimed at a person’s eye from close up, most or all of the light goes into the eye. This concentrated light is further focused by the eye onto a sharp dot on the retina. The power density from a 1 milliwatt laser, focused to a point, is brighter than the equivalent area of the sun’s surface. This can cause a detectable change (injury) to the retina, if the laser stays in one spot for a few seconds. That’s why in some countries such as the U.K., laser pointers are limited to 1 milliwatt or less.
Fortunately, people have a “blink reflex” where bright light causes blinking and/or moving out of the light. Because the blink reflex automatically limits the exposure time, lasers with an output less than about 5 milliwatts are generally considered safe for the public to use. (However, deliberate staring at a 5 milliwatt beam can cause blind spots. This has happened to drunk or stupid people.) The blink reflex effect is why the U.S. and some other countries allow laser pointers up to 5 milliwatts.
As laser power further increases, the beam becomes more hazardous. Even blinking may not help. Above roughly 50 to 100 milliwatts for visible continuous-wave lasers, even an accidental direct hit on an eye could cause retinal damage. If the person was looking straight at the laser, the burn will be in the center of a person’s vision. In extreme cases, central vision could be almost fully lost, and the person becomes blind in that eye.
Balloon-popping lasers are also burn hazards
Higher-power laser pointers can also be burn hazards. If a pointer can pop balloons, as some in the 250 milliwatt range can, then it could cause skin burns similar to hot wax, and of course it would be a serious eye hazard.
Don’t aim lasers at people
There are many danger factors. In general, the more powerful the laser, the closer a person is to the beam, and the longer the laser stays in the same area of the eye, the greater the possibility of eye damage.
Just as all guns should be treated as if they are loaded, all laser beams should be treated as potentially dangerous. For this reason, always keep any laser beam away from a person’s head and eyes.
How to stay safe and keep laser pointers legal
NEVER aim a laser beam at an aircraft, a vehicle, or towards strangers. In other words, DON’T ANNOY PEOPLE WITH THE LASER BEAM.