Children and teenagers are being found with serious eye damage after using laser toys.

There have already been reports from Europe and the US of teenagers going almost blind.

In Switzerland, a 15-year-old boy was found to have damaged his eyes while using a laser pointer he’d bought over the Internet.

The boy’s case was reported by doctors in Lucerne, Switzerland, where he was taken for treatment.

The doctors warned that the dangerously high-powered laser, which the boy had bought online, had been intended as a toy but had entered his eyes when the beam was reflected from a mirror.

The vision in his left eye was so poor when he was admitted that he couldn’t count fingers more than three feet away, while he could barely read a newspaper with the other eye.

British doctors, calling the laser a public health menace, said they had seen a teenager who had suffered serious damage to his eyes, while an adult man was affected for several months when his son zapped him in the eyes.

Laser pointers resemble pens and emit a narrow beam of laser light.

Used by teachers and lecturers to point out information during presentations, severe harm can be done if the beam enters the eyes.

In the US, laser pointers are not allowed to exceed an output limit of more than 5 milliwatts.