Although laser pointers are
popular tools for lectures, classroom teaching, and presentations and are often
even used as part of children’s toys, they can actually pose the risk of eye
injury.
What to Know About Laser Pointer Eye Injury Risk
The key fact to know about
laser pointer eye injury risk is that as
the power output increases above five milliwatts, the time margin for safe
exposure decreases and permanent eye and skin damage can occur quickly. The problem is that the output power of
laser pointers is not immediately apparent to the user. Laser pointers
often lack appropriate labeling or are mislabeled, and definitive testing of
individual pointers is beyond the reach of the average consumer. What we know for sure is that even the
briefest exposure to high-powered blue handheld laser products can cause
serious eye injuries.
Research on Laser Pointer Eye Injury
Researchers reporting in
Ophthalmology, found that if a laser
with less than five milliwatts of output power is directed at someone's eye,
that person can blink or turn away without suffering an eye injury. However,
the natural protective mechanisms of the eye-such as the blink reflex- are
ineffective against lasers with an output power greater than five milliwatts,
and severe retinal damage may occur, even after momentary exposure.
- Never aim or shine a laser pointer at anyone.
- Don't buy laser pointers for your children.
- Before purchasing a laser pointer, make sure
it has the following information on the label:
o a statement that it complies with Chapter 21 CFR (the Code of Federal Regulations);
o the manufacturer or distributor's name and the date of manufacture;
o a warning to avoid exposure to laser radiation; and
o the class designation, ranging from Class I to IIIa. Class IIIb and IV products should be used only by individuals with proper training and in applications where there is a legitimate need for these high-powered products.
The problem is that many
laser pointers lack labels or have inaccurate labels. Researchers found that 60
percent of the sampled laser pointer products that the FDA tests are
overpowered compared with what the label says. Those pointers may be powered in the 10s or 100s of milliwatts!
How do you know if your laser pointer is overpowered?
The FDA says that if you
have a laser pointer that isn't labeled or if you don't trust the labeling,
consider the following:
- If the pointer is small and runs on button
batteries, its output probably is less than five milliwatts.
- If it's pen-sized and runs on AA or AAA batteries,
it's likely to be more powerful and may exceed five milliwatts.
- If it's flashlight-sized and runs on a
cluster of AA or AAA batteries or runs on lithium batteries, it likely exceeds
five milliwatts.
- Pointers sold with battery chargers probably
drain their batteries quickly and are likely to be overpowered.
- Some pointers are sold with a removable cap
that spreads the beam into a pattern. If used without the cap, the beam
becomes a single beam that could exceed 5 milliwatts.
- Look for keywords that sellers might use to
indicate a pointer is highly powered without saying that it's over five
milliwatts: powerful, bright, ultra, super, military, military grade, super
bright, high power, ultra bright, strong, balloon pop, burn, burning,
adjustable focus, lithium battery, lithium powered.
- Look for videos or photos that show the laser
burning, melting, balloon popping or show a bright, well-defined beam of light.
- Look for purchaser comments on websites that
tout the brightness or power of the product.
Blue & Violet Laser Pointers Are the Most Dangerous!
Blue and Violet laser
pointers are the most dangerous because the human eye actually is less
sensitive to blue and violet. So, while a person would react quickly to a red
or green laser, that person may not blink or turn away as fast from an equally
powerful blue or violet light, creating a greater likelihood of injury.
Center for Sight is conveniently
located at 1565 North Main Street, Suite 406, Fall River, Massachusetts
02720 for patients
from Massachusetts or Rhode Island.
