Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Green laser pointer can cause eye damage


Mayo Clinic ophthalmologists have found commercially available Class 3A green laser pointers can cause visible harm to the eye’s retina with exposures as short as 60 seconds. The findings will be published in the May issue of Archives of Ophthalmology.

Dennis Robertson, M.D., Mayo Clinic ophthalmologist, conducted investigations with a green laser pointer directed to the retina of a patient’s eye; the eye was scheduled for removal because of a malignancy. The green laser damaged the pigment layer of the retina, although it did not cause a measurable decrease in the visual function of the patient’s eye. Dr. Robertson believes that longer exposures could harm vision, however. He also warns about potential damage from higher-powered green laser pointers. "With the use of laser pointers that are more powerful than five milliwatts, there would likely be damage to the actual vision," he says. "Functional damage could occur within seconds."

Dr. Robertson does not advocate against use of green laser pointers; rather, he advocates against their misuse. "Green laser pointers are not a public health hazard at this time, but something people should be aware of," he says. "I’m raising concerns that people should be cautious when using green laser pointers not to point them at someone’s eye or face. It’s like how you use your knife -- carefully." While pointing out risks of green laser pointers, he adds, "This is a potential hazard to people’s eyes, but rarely is it going to be a practical hazard because the aversion reflex we have naturally will cause a person to blink or turn away from a laser light."

Green laser pointers are readily available in stores and on the Internet, according to Dr. Robertson. "Kids can buy these," he says. "They’re not strictly regulated." He adds that Class 3A green laser pointers are increasingly being used by amateur astronomers to pinpoint objects in the night sky and by the construction industry and architecture educators to point out details of structures in daylight. Dr. Robertson conducted the eye exposure test with a consenting patient two weeks before eye removal due to ring melanoma. The patient’s vision was 20/20, and the macular retina appeared healthy.

Dr. Robertson exposed the patient’s retina to light from a commercially available Class 3A green laser with an average power measured at less than five milliwatts: 60 seconds to the fovea, the center of acute vision; five minutes to a site 5 degrees below the fovea; and 15 minutes to a site 5 degrees above the fovea. Dr. Robertson had color photographs taken of the eye before and after exposure to the laser.

Dr. Robertson examined the patient’s eye 24 hours after laser exposure. He found retinal damage characterized by yellowish discoloration involving the pigment layer beneath the fovea and at the site of the 15-minute exposure above the fovea. Each of these sites developed a grainy texture within six days. Study of the eye tissue under a microscope also confirmed damage to the pigment layer in the laser-exposed regions.

Dr. Robertson has been interested in the effects of lights on the human eye during his career, testing operating room microscopes, lights used in the clinic, red laser pointers and now green laser pointers.

Previously, he determined red laser pointers to be quite safe. "I tested different powers up to five milliwatts and could not create recognizable damage in the human eye with the red laser pointers," he explains. "So, at least a transient exposure to red laser pointers’ light is only of trivial concern."

Dr. Robertson attributes the risk differential between red and green lasers to wavelength. "We know that the retina is infinitely more sensitive to shorter wavelengths," he says. "The green lasers appear much brighter to the human eye because of the shorter wavelength and can cause damage." Dr. Robertson says Mayo Clinic’s investigations have clearly demonstrated that green laser pointers can cause irreversible damage to the pigment layer of the retina.

Lisa Lucier | EurekAlert!
Further information:

More articles from Health and Medicine:

nachricht Older patients recover more slowly from concussion
06.10.2015 | Radiological Society of North America

nachricht Fatty liver disease and scarring have strong genetic component
02.10.2015 | University of California - San Diego

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Physicists shrink particle accelerator

Prototype demonstrates feasibility of building terahertz accelerators

An interdisciplinary team of researchers has built the first prototype of a miniature particle accelerator that uses terahertz radiation instead of radio...

Im Focus: Simple detection of magnetic skyrmions

New physical effect: researchers discover a change of electrical resistance in magnetic whirls

At present, tiny magnetic whirls – so called skyrmions – are discussed as promising candidates for bits in future robust and compact data storage devices. At...

Im Focus: High-speed march through a layer of graphene

In cooperation with the Center for Nano-Optics of Georgia State University in Atlanta (USA), scientists of the Laboratory for Attosecond Physics of the Max Planck Institute of Quantum Optics and the Ludwig-Maximilians-Universität have made simulations of the processes that happen when a layer of carbon atoms is irradiated with strong laser light.

Electrons hit by strong laser pulses change their location on ultrashort timescales, i.e. within a couple of attoseconds (1 as = 10 to the minus 18 sec). In...

Im Focus: Battery Production: Laser Light instead of Oven-Drying and Vacuum Technology

At the exhibition BATTERY + STORAGE as part of WORLD OF ENERGY SOLUTIONS 2015 in Stuttgart, the Fraunhofer Institutes for Laser Technology ILT and for Ceramic Technologies and Systems IKTS will be showing how laser technology can be used to manufacture batteries both cost- and energy-efficiently.

In the truest sense, it’s all about watts at the Dresden-based Fraunhofer Institute for Ceramic Technologies and Systems IKTS and the Aachen-based Fraunhofer...

Im Focus: New Sinumerik features improve productivity and precision

EMO 2015, Hall 3, Booth E06/F03

  • Drive optimization called automatically by the part program boosts productivity
  • Automatically switching the dynamic values to rapid traverse and interpolation...
All Focus news of the innovation-report >>>



Event News

EHFG 2015: Securing healthcare and sustainably strengthening healthcare systems

01.10.2015 | Event News

Conference in Brussels: Tracking and Tracing the Smallest Marine Life Forms

30.09.2015 | Event News

World Alzheimer`s Day – Professor Willnow: Clearer Insights into the Development of the Disease

17.09.2015 | Event News

Latest News

Graphene teams up with two-dimensional crystals for faster data communications

06.10.2015 | Information Technology

Laser-wielding physicists seize control of atoms' behavior

06.10.2015 | Physics and Astronomy

Flipping molecular attachments amps up activity of CO2 catalyst

06.10.2015 | Life Sciences

More VideoLinks >>>