Used incorrectly, laser pointers can damage the retina of the eye and may cause some irreversible vision loss, according to researchers who treated four boys for these injuries.
Doctors, teachers and parents should be aware that this can happen, and limit children's use of laser pointers, the authors write.
"This was initially thought of as a never event, that never happened," said senior author Dr. David R. P. Almeida of VitreoRetinal Surgery, PA, in Minneapolis, Minnesota. "But we have four cases so it does happen sometimes," though it's still unusual.
The authors report on two 12-year-olds, one nine-year-old and one 16-year-old who came to a medical center with central vision loss and "blind spots" within hours to days after looking into or playing with a green or red laser pointer.
In one case, the boy looked at the reflection of a laser pointer in a mirror. Two others simply pointed the lasers at themselves, and the fourth was engaged in a "laser war" with a friend.
The researchers report in Pediatrics that three of the boys had potentially irreversible, although relatively mild, vision loss. One boy's vision continued to worsen two weeks after the injury and eventually decreased to 20/40 best corrected visual acuity in both eyes, which is at or close to the limit for obtaining a driver's license in most U.S. states.
"Long-term outcomes for these patients will be pretty mild vision loss," Almeida said.
"Males may horse around with things more, or we just happened to have boys in our series," Almeida told Reuters Health by phone. Injuries could be just as likely for girls.
He advises parents to be careful about where they buy laser pointers, as some retailers may not list the power rating or may list it incorrectly, and to limit use for kids under 14.
Most consumer laser pointers fall under class II or class IIIA level of safety according to the American National Standard Institute, with a power output of five milliwatts or less. But class 3B or class 4 level lasers may emit up to 500 milliwatts or more and these lasers may cause immediate eye hazard when viewed directly, Almeida and his coauthors write.
Retinal tissue in the back of the eye leads to the brain, and it has no ability to regenerate after tissue loss, Almeida said.
"One patient developed bleeding and needed an injection in the eye," which can be particularly unpleasant for children, he said.
Kids may use laser pointers as long as they avoid improper use, Almeida said.
"Unsupervised use of these laser pointer devices among children should be discouraged, and there is a need for legislation to limit these devices in the pediatric population," he and his coauthors write.