Green light : the most dangerous kind

Laser pointers are classified in 4 categories depending on their power, thus their dangerousness. Only the two first categories are authorized for consumers in Europe. The Austrian’s pointer, made in china, was bought online on a selling website. It was presented as a category 2, usually tolerated in Europe in spite of the fact that it can cause lesions in less than 0.25s of exposition.

The medical review Jama Ophthalmology reminded at the beginning of the year that powerful laser pointers should never be aimed at the eyes of a person, and shouldn’t be used in the presence of infants. This light easily penetrate the eyes, said Professor Gilles Renard, Scientific director of the French society of ophthalmology when contacted by Le Figaro. Absorbed by the retina, it can cause the coagulation of vessels that translates into a permanent or temporary reduction of central vision.

The severity of the lesions depend on the laser’s power and the time of exposition. Lasers with a power exceeding 1 mW are usually banned. But it is easily found on the internet with powerful models (category 3 or 4), usually destined to a professional use. According to Professor Renard, the most dangerous types of laser pointers are those that emit a green light, their power could reach 5000 mW (blue laser). If projected to the eye at close range, the light could burn the retina and leave irreversible scarring.