Handheld laser pointer can cause eye injury and blindness
Laser pointers often used in classrooms and lecture halls can cause severe eye damage and consequent vision loss.
In an article published in The New England Journal of Medicine, submitted by a group of doctors from Lucerne Cantonal Hospital in Switzerland, a 15-year-old boy who played with a high-power laser pointer purchased over the Internet sustained retinal injury in both eyes (retina is a membrane lining at the back of the eye that detects light and images). He experienced immediate blurred vision when the laser beam hit his eyes several times after playing with the laser in front of a mirror. On examination, hemorrhage and swelling in the retina of his left eye caused by a laser burn were seen. Several tiny scars were also found in his right eye.
The FDA set the standard for certain types of laser, such as bar code scanners and laser pointers, at 5 milliwatts (mW). In the above case, the teenager used a laser pointer with green light powered at 150 mW.
Laser pointers with maximal output of 5 mW (Class IIIa) are classified as harmless because their intensity can be shielded by the protective human eye blink reflex; although staring directly into the 5 mW beam for a prolonged period will cause eye injury.
Manufacturers of laser products that are powered above 5 mW are required to obtain FDA permission before they sell to the pub¬lic. The FDA is concerned about the growing availability in stores and on the Internet of laser products sold illegally above 5 mW. In fact, according to the FDA consumer health information, there are laser toys or other laser prod¬ucts that are powered above 5 mW after the batteries that come with them are replaced with fresh bat¬teries.
The authors in this case also observed that laser devices advertised as “laser pointers” with a power up to 700 mW, and that look identical to low-power pointers, are easily obtainable through the Internet, despite government restrictions. Websites are now also selling laser swords and other high-powered laser gadgets.
An earlier study in 2007 published in Pediatric Emergency Care recommended that significant direct eye exposure to a laser, persistent afterimages and decreased visual acuity should initiate urgent referral to an ophthalmologist.
The FDA advised consumers to look for the label stating compliance with federal regulations, the manufacturer's or distributor's name and the date of manufacture, a warning to avoid exposure and a class designation up to Class IIIa.