Dr. Kayla Bechthold Blog: How dangerous are lasers to your eyes? Pretty Dangerous.
Handheld lasers or laser pointers have conventionally been considered safe for eyes. However, there has been an increase in laser pointer eye injuries over the last few years.
This could be attributed to the ease with which laser pointers can be purchased online, and how little the FDA is able to control these purchases. The most common injuries are suffered by males under age 18.
Laser eye injuries vary greatly depending on the strength of the laser, the type of light it emits, and exposure time.
There are five laser classifications. Class I are considered safe from all hazards, they include CD players and laser printers. Class II are less than 1mW, these include laser pointers commonly used in classrooms and aiming devices. Damage is caused by looking directly into the light for more than 15 minutes.
Class IIIa include 1-5mW devices. Some laser pointers do fall into this class. Direct viewing of the beam can be hazardous to the eyes, even for brief amounts of time. The American National Standards Institute (ANSI) is the body that regulates lasers manufactured and sold in the US. ANSI standards classify that all laser pointers must be Class IIIa or less.
Handheld lasers can be more powerful, and the last two classes of lasers fall into this category. Class IIIb lasers include 5-500mW devices. These lasers are used in spectrometry or entertainment laser light shows. Direct viewing of this laser light is hazardous to the eyes, even briefly.
Class IV lasers are stronger than 500mW. They are commonly used in surgery, for drilling, cutting or welding. These easily damage eyes and skin.
Consumers are generally unaware that a laser pointer or handheld laser can be so dangerous. Also, the specs on the side of the laser do not always match the output the laser actually has. Oftentimes when the actual light emitted from the laser is measured it is many times more powerful than what is on the label 1.
Also, different colors of lasers can be more dangerous. A thought would be that reactively we can protect ourselves from the laser light by just quickly closing our eyes. However, often there are infrared light rays mixed with the green or red light, which are not in the visual spectrum. We do not have an aversion response to these rays, and therefore may look at them longer. Blue and violet lasers are alarmingly high powered and can cause damage before there is a chance to close one’s eyes 2.
The damage to the eyes varies from temporary flash injuries (which usually happen with low powered lasers) to macular holes and permanent central retinal injury. The macula is the area in the retina that is responsible for central vision, and if it is damaged it can result in severe visual acuity decrease. There are cases of laser injury resulting in legal blindness 3.
Treatment is controversial and still being studied, but an ophthalmologist or optometrist should be consulted immediately if damage is suspected. If appropriate, that provider will refer to a retinal specialist also.
How can we protect ourselves and our children from this danger? The FDA has published guidelines for consumers regarding laser pointers and handheld lasers 4.
1. Never aim or shine a laser pointer at anyone.
2. Don’t buy laser pointers for your children.
3. NO LASER OVER 5mW- these are illegal.
4. 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 FDA also recommends 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 5mW.
· If it’s pen-sized and runs on AA or AAA batteries, it’s likely to be more powerful and may exceed 5mW.
· If it’s flashlight-sized and runs on a cluster of AA or AAA batteries or runs on lithium batteries, it likely exceeds 5mW.
· 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 5mW.
· Look for keywords that sellers might use to indicate a pointer is highly powered without saying that it’s over 5mW: 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.
Most times common sense is the best defense from these types of injuries. But, with laser related eye injuries being on the rise, and with the technology so easily accessible, it’s important to stay informed.
The following is a video by the FDA regarding laser safety.
If you have any questions or need to schedule an eye exam, please contact us at 218-254-4393.
1 Hadler J, Tobares E, Dowell M. Random testing reveals excessive power in commercial laser pointers. J Laser Appl. 2013;25:032007. 2 Lee,GregoryD., MD, and David R. Lally, MD. “Laser Pointer Retinal Injuries.” Apr. 2015:n.pag. Print 3 Soglin Ari. Is Your Laser Pointer Dangerous Enough to Cause Eye Injury? EyeSmart. Dec. 20, 2013. http://www.aao.ort/eye-health/news/laser-pointer-eye-injury 4 http://www.fda.gov/Radiation-EmittingProducts/RadiationSafety/AlertsandNotices/ucm15348.htm