It has long been known that laser pointers can be damaging to the eyes, but apparently this is not widely known. Injuries to the eyes (retinal injuries) causing irreversible vision loss are rapidly increasing from them, especially among children. Injuries to the eye happen when a person stares directly into the laser pointer, or even into the reflection in a mirror. This can inadvertently happen among children, for example when playing games such as laser tag.
A laser pointer is a small handheld device that contains a small diode laser that emits a very narrow beam of light, used to highlight something of interest.during presentations. They are also inappropriately used as toys for some children. The researchers point out that "green laser pointers are becoming increasingly more popular and abundantly available, which is concerning because experiments reveal that green laser pointers (490–575 nm) are more harmful to the retina compared with red laser pointers (630–750 nm)". From Medscape:
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.
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 September 1st 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.
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.