Sep. 8, 2010 at 5:02 PM ETTurns out mom was right, yet again. You can put your eye out playing with unsafe toys. The “toy” in this case was a handheld laser, purchased online by a 15-year-old Swiss boy. According to a letter published in today’s New England Journal of Medicine, the boy had ordered a laser pointer with a green light “to use as a toy for popping balloons from a distance and burning holes into paper cards and his sister’s sneakers.” Unfortunately, he ended up burning holes in his retinas instead by pointing the laser at a mirror while trying to create a “laser show.” “He had remarkably reduced vision. He was unable to read a newspaper,” says Dr. Martin Schmid, who treated the boy and penned the letter to NEJM warning of the risk of handheld lasers. Laser pointers look like pens but shoot out a laser beam. They're often used by lecturers giving presentations, but more powerful versions are used by the military for long-distance signaling. Burning eyes? Blame the cows According to Schmid, who heads the retina unit at Lucerne Cantonal Hospital’s department of ophthalmology in Lucerne, Switzerland, the boy noticed blurred vision immediately after the laser hit his eyes, but was afraid to tell his parents. Instead he waited two weeks, hoping his vision would clear up. Doctors discovered a hemorrhage in his left eye and scarring in his right. Vision in his left eye improved from 20/50 to 20/25 after doctors gave him an injection -- directly into the eyeball -- of ranibizumab, a drug normally used for people suffering from age-related macular disease. Sadly, the boy’s retinal damage is permanent. Your new nightmare worms its way into view “The visual acuity will remain reduced,” says Schmid, who says laser pointer-related accidents like this have happened before and are likely to happen again due to the easy availability via the web. All lasers have to be classified and labeled, but Schmid says many are not -- and kids and parents often don't realize these tools are real and powerful lasers. The Swiss boy was playing with a laser with an output of 150mW -- that's 30 times the power limit imposed by the Food and Drug Administration for sale in the U.S. Lasers found online often exceed that limit. The doctor warns no matter what type of laser, people should never shine a laser beam in their eyes or anyone else’s. Share your stories of teen hijinks turned hazardous in the comments. Find The Body Odd on Twitter and on Facebook.