Eye Injury & Laser Pointer Safety
Given the widespread use of laser pointers, the possibility and ways in which they pose a risk to eye safety and cause eye injury is often overlooked. Laser pointers are very commonly used in the classroom, business meetings, at presentations and lectures-but did you know that they are also sold as toys? This could be a cause for concern as the greater a laser pointer's output power, the more likely it will cause serious eye injuries. Understanding the safety of that laser pointer in your desk drawer or in your kid's hand isn't always obvious but we can share some information that may be useful.
Laser Pointer Basics
As laser power increases
above five milliwatts, the time margin for safe exposure decreases, meaning
that permanent eye and skin damage can occur quickly. However, the challenge 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.
Researchers reporting the
results of a study in Ophthalmology,
the journal of the American Academy of 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.
Here's what the FDA advises:
- 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:
- a statement that it complies with Chapter 21
CFR (the Code of Federal Regulations);
- the manufacturer or distributor's name and
the date of manufacture;
- a warning to avoid exposure to laser
radiation; and
- 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 and the 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?
Ideally, consumers could
buy a laser pointer with the certainty that it's powered under five milliwatts
but this isn’t possible based on the poor labeling and compliance.
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.
If you or someone you know is concerned about laser pointer
use and eye safety, please have them call Doctor &
Associates-203-227-4113, visit Doctor
& Associates or facebook.com/doctorandassociates to schedule an
appointment.
Doctor & Associates offices
are located at 129 Kings Highway North, Westport, Connecticut 06880, 195
Danbury Road, Wilton, Connecticut 06897 and 148 East Avenue, Norwalk,
Connecticut 06851.