Safety Recommendations for Laser Pointers.
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.
While the majority of the laser pointers contain low to moderately powered diode lasers, more powerful lasers can be found on the market, usually imported from other countries. These pointers present a significant potential for eye injury and are often not properly labeled according to FDA regulations.
There are currently no restrictions for purchasing laser pointers in the United States. The FDA hasissued a warning for laser pointers, urging that the pointers be used as intended, not as toys, and not by children unless under adult supervision. The full text of the FDA warning is included as Appendix A.
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 3R 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. Some of these lasers emit green beams from frequency doubled Nd:YAG lasers operating at 532 nm and have emissions significantly exceeding the maximum permissible exposure (as per the ANSI laser standard, Z136). One of the lasers has a filter in the cap, which, if removed, allows the laser to emit both 532 nm and 1064 nm beams, in excess of 15 mW, making it an even more hazardous Class 3b laser.
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 3R), the maximum output power (in milliwatts mW) and the wavelength. It is prudent not to purchase or use unlabeled laser pointers.
Potential Hazards
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 Accidents and Incidents
As laser pointers become more ubiquitous, more and more laser pointer related incidents have been reported worldwide. Most of the reports do not concern eye exposure, but outrage. For example, police officers have reportedly drawn their weapons when the light from laser pointers is mistaken for a gun sight. Laser beams projected into airspace and intercept aircraft have caused distractions and temporary vision impairment to pilots.
Several individuals have reported temporary blindness when targeted by a number of laser pointers. This is becoming more prevalent at sporting events. A few individuals complained of afterimages lasting several days.
A high school cheerleader reported being exposed at least three times. After the last episode, she reported first seeing "green", then experiencing partial vision loss, which lasted for several months. An ophthalmic exam found no retinal damage.
Safety Considerations
Laser pointers are effective tools when used properly. The following considerations should be observed when using laser pointers:
Never look directly into the laser beam.
Never point a laser beam at a person.
Do not aim the laser at reflective surfaces.
Never view a laser pointer using an optical instrument, such as binocular or a microscope.
Do not allow children to use laser pointers unless under the supervision of an adult.
Use only laser pointers meeting the following criteria
Labeled with FDA certification stating "DANGER: Laser Radiation" for Class 3R lasers or "CAUTION: Laser Radiation" for Class 2 pointers.
Classified as Class 2 or 3R according to the label. Do not use Class 3b or 4 products.
Operates at a wavelength between 630 nm and 680 nm.
Has a maximum output less than 5 mW, the lower the better.
For more information
Contact Robin Izzo at
rmizzo@princeton.edu or 258-6259.
Appendix A
FDA Issues Warning on Misuse of Laser Pointers
The Food and Drug Administration is warning parents and school officials about the possibility of eye damage to children from hand-held laser pointers.
These products are generally safe when used as intended by teachers and lecturers to highlight areas on a chart or screen. However, recent price reductions have led to promotion and use of these products as children's toys.
The light energy that pointers can aim into the eye can be more damaging than staring directly into the sun. Federal law requires a warning on the product label about this potential hazard to the eyes.
" These laser pointers are not toys. Parents should treat them with appropriate care," said FDA Lead Deputy Commissioner Michael A Friedman, M.D. "They are useful tools for adults that should be used by children only with adequate supervision."
The FDA's warning is prompted by two anecdotal reports it has received of eye injury from laser pointers -- one from a parent, the other from an ophthalmologist.
Momentary exposure from a laser pointer, such as might occur from an inadvertent sweep of the light across a person's eyes, causes only temporary flash blindness. However, even this can be dangerous if the exposed person is engaged in a vision-critical activity such as driving.
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Safety Recommendations for Laser Pointers
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