Retinal Injuries from a Handheld Laser Pointer

According to a case study published in the Sept. 9 issue of the New England Journal of Medicine, a 15-year-old Swiss boy damaged his eyes while playing with a laser pointer he'd bought over the Internet, say doctors who warn that dangerously high-powered versions are easily available online.

The pointer used by the teen was "30 times more powerful than the FDA limit." After playing with it in front of a mirror to create a light show...he accidentally zapped his eyes with its green light several times.

The majority of the laser pointers used in the U.S. have either Class 2 lasers with a maximum power output of less than 1 mW or Class 3R diode lasers in the 630-680 nm wavelength (red), with a maximum power output of between 1 and 5 mW. All laser pointers should have a small sticker on them with either a yellow "Caution" or black and red "Danger" insignia, the laser classification (2 or 3R), the maximum output power (in milliwatts mW) and the wavelength. It is prudent not to purchase or use unlabeled laser pointers.

Retinal injuries from lasers can result from ablative, thermal, or photochemical mechanisms depending on power, wavelength, exposure time, and size of pupil.

Laser pointers are effective tools when used properly. The following considerations should be observed when using laser pointers:

• Never look directly into the laser beam.
• Never point a laser beam at a person.
• Do not aim the laser at reflective surfaces.
• Never view a laser pointer using an optical instrument, such as binocular or a microscope.
• Do not allow children to use laser pointers unless under the supervision of an adult.
• Use only laser pointers meeting the following criteria
  • Labeled with FDA certification stating "DANGER: Laser Radiation" for Class 3R lasers or "CAUTION: Laser Radiation" for Class 2 pointers.
  • Classified as Class 2 or 3R according to the label. Do not use Class 3b or 4 products.
  • Operates at a wavelength between 630 nm and 680 nm.
  • Has a maximum output less than 5 mW, the lower the better.

Posted in: Laser pointer, Physics