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Are Laser Pointers Dangerous?

Laser pointers can be dangerous if pointed directly at the eyes.
Staring into a laser through a fully dilated eye for over one minute may cause a retinal burn.
Laser pointers are commonly used in lecture halls.
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  • Written By: Mary McMahon
  • Edited By: Bronwyn Harris
  • Last Modified Date: 30 July 2014
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Laser pointers are visible lasers with a relatively low power output which are frequently used in lecture halls and demonstrations to point at topics of interest on a presentation board. In a school setting, they have become ubiquitous, and they are very useful teaching aids. A drop in the price of laser pointers has also led to increased use among the general population. More common use of these devices has raised concerns about their safety, especially around the eyes.

The biggest concern with laser pointers and the eyes is temporary optical problems. These issues include flash blindness, glare, and afterimages. Flash blindness occurs whenever someone is exposed to a bright light source. While it only lasts for a few seconds, it can be extremely dangerous when someone is involved in a task which requires vision, such as driving. Afterimages can last for several days, and take the form of small spots in the vision. Glare, a reduction of visibility caused by bright light, occurs while the laser is directed at the eyes.

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Fortunately, the eye problems most commonly associated with laser pointers do not take the form of permanent damage. Reduction of visibility can certainly represent a danger, however, and these devices should be used with care for this reason. More profound optical damage can also result, if the exposure is prolonged. Most laser pointers have a very low power output, but when it is focused on the retina through the lens of the eye, it can cause damage. Continuously staring into a laser through a fully dilated eye for over one minute may cause a retinal burn.

In most regions, the labeling of laser pointers is regulated. The device should have a “caution” label which also indicates which class the laser is in, and the power output. Many laser pointers are IIIA devices, meaning that there is a potential for damage with direct exposure to the laser. Class two lasers are less powerful, and are a better choice if you are concerned about safety. However, the lower light output may not be effective in a lecture hall.

If used responsibly, a laser pointer should not present a danger. It should never be used as a toy or pointed directly at someone else. When using a laser pointer outdoors, be aware of passing cars and aircraft, as there have been documented instances of issues related to lasers in the eyes of pilots and drivers. Do not let a child use this device, and if you find one pointed at your eye, move and remind the person pointing it at you that these devices should not be directed toward someone's face.

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anon955444
Post 8

I work in the entertainment industry as a stand in for actors. As the crew is setting up the shot, the camera assistants point laser pointers at our faces to check the distance so they can "pull focus" for the cameras. The lasers occasionally hit me directly in the eye. How dangerous are these distance finding lasers? (The beam in always red, if that helps.) Thanks.

anon258562
Post 5

I bought a laser at the dollar store, and it is labelled 100MW.

Maybe my batteries are weak, because I'm not getting anywhere close to that output.

ildadirect
Post 4

anon87709: If you aimed 100 laser pointers at the same spot, yes, the spot would have 100 times the laser energy on that spot. In a general sense it would be 100 times as dangerous as one of the laser pointers.

However, there is also the factor that the spot is the only place all the beams come together. Let's say the 100 pointers are arranged in a 10 x 10 grid, each 1 inch apart. The beams are all aimed to meet at a spot 10 feet away. Well, after they meet, the beams will separate again. 20 feet from the laser pointers, the beams will be a 10 x 10 matrix of beams on the wall, each beam 1 inch from the other.

This relates to eye safety because the eye would have to be in just the right location to get all 100 beams through the pupil. And then the beams spread out slightly onto the retina so the spot is larger.

It still is dangerous and hazardous; however, the overall hazard is technically less than a single laser that is 100 times more powerful than one of the laser pointers.

ildadirect
Post 3

anon124353: For visible continuous lasers, Class IIIb or 3B goes from 5 mW to 500 mW. Class IV or 4 goes from 500 mW on up. You have a 1000 mW (1 watt) laser so it is definitely Class 4. This is the most hazardous classification.

You should wear laser safety goggles or glasses which are appropriate to the wavelength (color) and power of your laser. But be careful -- safety glasses alone can give a false sense of security. People forget to put on the glasses, other people walk into the room, the laser is still a burn hazard, etc.

anon124353
Post 2

I just bought a 'military grade' 'laser pointer' and I'm a bit worried now. it says its 1000mW and on the side it says 'IIIb' - does that mean it's more powerful and dangerous? should I be wearing glasses when I split the beam for a laser scanning project I'm working on?

anon87709
Post 1

Well what would happen if you tied 100 laser pointers together and aimed them at someone at night? Would it not be much brighter and cause even more damage to eyesight.

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