Can Laser Pointers Hurt Your Eyes
Laser pointers have become commonplace since they are an effective tool to aid in presentations and inexpensive. Many people are concerned that laser pointers will hurt their eyes if they look at the laser light. So can laser pointers hurt your eyes? If you look at a laser pointer for a few seconds should you be concerned?
The most common problem associated with laser pointers and the eye is a condition called flash blindness. Flash blindness occurs when the eye becomes dazzled after being exposed to a bright light. Most people have experienced flash blindness after having their picture taken by a camera with a flash. This condition is temporary and most people regain their vision after a minute or so. Flash blindness can be dangerous if it occurs while someone is performing a visually demanding task such as driving a car. There have been several reported incidents of airline pilots becoming flash blind after someone on the ground aimed a laser pointer at the cockpit. In 2010 alone, the Federal Aviation Administration said they had recorded 2,836 such instances.
Permanent damage to the eye can result from retinal damage. The retina is a tissue that lines the back of the eye and is responsible for capturing the image we see and sending it to the brain resulting in the perception of vision. If the retina is damaged, then permanent vision loss can result. So a laser can cause permanent vision loss if it damages the retina.
In the United States, lasers are regulated by the Food and Drug Administration. Lasers typically have a warning label alerting the consumer to the danger. Most lasers used in toys and games are labeled type I. Type I lasers have a power output of under .4 milliwatts and are incapable of damaging the retina. Most laser pointers are classified as type II or IIIA and have a power output of between 1 to 5 milliwatts. Theoretically, that is enough power to damage the retina. A paper published in the journal Ophthalmology in 1997 demonstrated retinal damage with continuous exposure to light from a laser pointer in as little as 10 seconds. In practice it would be difficult to damage the eye because the eye makes lots of tiny eye movements causing it to be almost impossible to achieve 10 seconds of continuous exposure. No cases of permanent damage from laser pointers labeled type II or IIIA have been reported in the literature.
Recently, a paper was published in the New England Journal of Medicine demonstrating permanent vision loss in a 15 year-old in Switzerland who ordered a laser off the internet. The laser was not regulated and had a power output of 150 milliwatts, which is 30 times more powerful than laser pointers sold in the United States. The boy was using the laser to burn holes in paper and to pop balloons. The boy shined the laser in his eye and suffered permanent, moderate vision loss.
Conclusion: Myth Confirmed
While it is unlikely most lasers used in toys, games, and laser pointers can permanently damage your eyes, it is theoretically possible so caution should be exercised. However, spilt second exposure from type II or IIIA laser pointers will not result in any permanent damage. Shining a laser pointer in someone’s eye performing certain visual tasks can cause flash blindness and result in an accident. Children should never play with lasers unsupervised and no one should use a laser that is not properly labeled by the United States Food and Drug Administration. It is possible to order very powerful lasers over the internet and there use is definitely dangerous.