Laser pointers are very often used in classrooms, lecture halls, during presentations and even as toys. But did you know that laser pointers can be a potential source of eye injury? Specifically, the greater a laser pointer's output power, the more likely it will cause serious eye injuries. Having a better understanding of the “do’s & don’ts’ of laser pointers as well as the potential for eye injuries as related to their strength and power, can go a long way to making that laser pointer on your desk or in your child’s hand a safe and useful tool.
Laser Pointer Output Strength
As the power increases above five milliwatts, the time margin for safe exposure decreases and permanent eye and skin damage can occur quickly. However, 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 has less than five milliwatts of power, however 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 contact D’Ambrosio Eye Care by calling us at 800-325-3937, visiting D’Ambrosio Eye Care or facebook.com/dambrosioeyecare so that we can help answer questions.
D'Ambrosio Eye Care provides eye care for patients throughout greater Boston, central and western Massachusetts with office locations at 479 Old Union Turnpike, Lancaster, Massachusetts 01523, 100 Powder Mill Road, Acton, Massachusetts 01720, 413 Main Street, Athol, Massachusetts 01331 and 74 Main Street, Gardner, Massachusetts 01440.