A report from a British hospital says that laser pointers can cause eye damage which may persist for up to 10 months after the injury.
Doctors followed 14 patients who attended the Bristol Eye Hospital after their eyes had been exposed to the beam of a laser pointer. They found that, after exposure, all but one of the patients had eye discomfort or some form of impaired vision.
The most common subjective complaints were pain (11 patients), blurred vision (9 patients) and headache (2 patients), and the most common objective sign was red eyes (caused by rubbing the eye after the incident; 5 patients). On follow up 10.5 months later, two of the patients had persisting visual problems for which they had consulted an optician.
Many laser pointers are sold without any warning about their use. Some emit as much as 5 megawatts of power enough to damage the eye within seconds. In nine of the 14 cases studied, exposure happened in the workplace (Br J Opthalmol, 1999; 83: 1164-7).