Green laser pointers can damage eyes
A woman damaged her eye after spending only seconds looking directly at a green laser pointer, suggesting that these lasers can be more dangerous in green than in red, experts say.
After the woman looked directly at the green laser for different periods of time, including as little as 60 seconds, researchers saw that portions of her retina had changed color, a sign of damage. The woman never experienced any loss of vision, and by 3 weeks, the damage was healing.
The lead author suggested that if the woman had spent longer looking at the laser, her eyesight might have suffered as a result.
"With longer exposures, she could have visual loss,” said Dr. Dennis M. Robertson of the Mayo Clinic in Rochester, Minnesota.
He added that previous studies have shown that looking directly at a red laser pointer for up to 15 minutes cannot produce the same damage this woman experienced after only 60 seconds looking at a green laser. “The eye is much more vulnerable to damage from the green laser pointer than the red laser pointer,” he said in an interview.
Robertson explained that green is made up of shorter wavelengths than red, and the retina is more sensitive to shorter wavelengths. He recommended that people think of the green laser as they do the sun—okay to glance at occasionally, but dangerous if looked at too long.
To investigate how the green laser might damage eyes, Robertson and his team asked a 55 year-old woman with cancer in her eye—for which the only treatment was removal of the eye—to look directly at a class 3A green laser pointer for different stretches of time, before she underwent surgery to remove the eye.
After the experiment, the researchers saw that a portion of her retina had changed from its normal color of orange-red to yellow, a sign the laser had damaged the retina.
In the Archives of Ophthalmology, a medical journal, the researchers note that the damage matched what people can do to their eyes after staring at a solar eclipse.
Robertson said that people use laser pointers for many reasons, such as giving lectures. Green lasers are less popular than red lasers, he said, but green is easier to see in the night sky, and is therefore often preferred by amateur astronomers.
SOURCE: Archives of Ophthalmology, May 2005.
Print Version
Tell-a-Friend
