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Introduction
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 are now being imported from China. 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 issued 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.
The United Kingdom banned the sale and use of laser pointers, with the
exception of low powered pointers (Class 2). This was promulgated in response
to a number of reported incidents involving laser pointers and a study
by Herriot-Watt University that found that the majority of the laser pointers
they tested did not meet their safety regulations.
The majority of the laser pointers used in the U.S. use Class 3a diode
lasers in the 630-680 nm wavelength (red), with a maximum power output
of between 1 and 5 mW. The length of exposure to visible lasers is usually
limited by the eye's blink reflex, which normally occurs within a quarter
of a second. Theoretically, Class 3a lasers could cause injury to the eye
if viewed directly for less than .25 seconds.
Most laser pointers manufactured before 1993 were Class 2 lasers, with
a power output of less than 1 mW. These lasers are safe to view directly
for short periods of time.
A recent report by James Rockwell, et al, in the Journal of Laser
Applications noted that more powerful laser pointers are now being
imported from Russia and China. Some of these lasers lack the appropriate
warning labels. 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.
The same article noted a recent advertisement for a "super power diode
pointer that is 20 times brighter than other conventional lasers."
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 retinal damage. The possible
exception might be the green light lasers described above.
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.
Over the past two years, 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.
Laser pointers are effective tools when used properly. The following
considerations should be observed when using laser pointers:
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Never look directly into the laser beam.
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Never point a laser beam at a person.
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Do not aim the laser at reflective surfaces.
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Never view a laser pointer using an optical instrument, such as binocular
or a microscope.
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Do not allow children to use laser pointers unless under the supervision
of an adult.
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Use only laser pointers meeting the following criteria
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Labeled with FDA certification stating "DANGER: Laser Radiation" for Class
3a lasers or "CAUTION: Laser Radiation" for Class 2 pointers.
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Classified as Class 2 or 3a according to the label. Do not use Class 3b
or 4 products.
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Operates at a wavelength between 630 nm and 680 nm.
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Has a maximum output less than 5 mW, the lower the better.
For more information
Contact Radiation Safety at Radiation Safety
or 206.543.0463.
FDA Issues Warnings on Misuse of Laser Pointers
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The Food and Drug Administration is warning parents and school officials
about the possibility of eye damage to children from hand-held laser pointers.
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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.
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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.
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"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."
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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.
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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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