The use of laser pointers has become widespread. The pointers are useful tools for educators in the classroom and at conventions and meetings. However, due to the low cost and ubiquitous supply, these pointers are now being purchased and used by the general public, including children, and used in ways not intended by the manufacturers. As a result, serious concerns about the hazards of laser pointers have surfaced.
Types of Laser Pointers
The majority of the laser pointers used in the U.S. have either Class 2 lasers with a maximum power output of less than 1 mW or Class 3a diode lasers in the 630-680 nm wavelength (red), with a maximum power output of between 1 and 5 mW.
There have been reports of more powerful laser pointers imported from Russia and China that lack the appropriate warning labels and have laser beam emissions exceeding the maximum permissible exposure recommended by the American National Standards Institute (ANSI Z136). These laser pointers theoretically could cause significant damage to the eye.
All laser pointers should have a small sticker on them with either a yellow "Caution" or black and red "Danger" insignia, the laser classification (2 or 3a), the maximum output power (in milliwatts mW) and the wavelength. It is prudent not to purchase or use unlabeled laser pointers.
The hazards of laser pointers are limited to the eye. Although with most visible lasers, the largest concern is potential damage to the retina, most laser pointers are not likely to cause permanent retinal damage.
The most likely effects from exposure to viewing the beam from a laser pointer are afterimage, flashblindness and glare. Flashblindness is temporary vision impairment after viewing a bright light. This is similar to looking directly at a flashbulb when having a picture taken. The impairment may last several minutes.
Afterimage is the perception of spots in the field of vision. This can be distracting and annoying, and may last several minutes, although there have been reports of afterimages lasting several days.
Glare is a reduction or complete loss of visibility in the central field of vision while being exposed to the direct or scattered beam. This is similar to viewing oncoming headlights on a dark night. Once the beam is out of the field of vision, the glare ceases. While this does not pose a hazard to the eye, it can cause serious distraction and outrage. Glare can be exacerbated when the beam is reflected from a mirror-like surface.
Laser Pointer Tips
- Never shine a laser pointer at anyone. Laser pointers are designed to illustrate inanimate objects.
- Do not allow minors to use a pointer unsupervised. Laser pointers are not toys
- Do not point a laser pointer at mirror-like surfaces. A reflected beam can act like a direct beam on the eye.
- Be aware of irresponsible uses of pointers so the psychological effect will be minimized if you are illuminated by one.
- Do not purchase a laser pointer if it does not have a caution or danger sticker on it identifying its class. Report suspicious devices to the FDA.