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Laser pointer use during protests

This page discusses the use (and misuse) of lasers during protests, demonstrations, riots and other civil disturbances. Shown below are protesters in Hong Kong in August 2019. Lasers have been used in many other demonstrations as well, both worldwide and in the U.S.'s 2020 protests. Sometimes persons are arrested at protests for misusing laser pointers.
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This is one of 21 striking photos in a November 19 2019 collection by Alan Taylor in The Atlantic called "The Lasers of Discontent." These photos give a dramatic overview of the tremendous numbers of lasers that have sometimes been arrayed against police and security forces. The photos are all or mostly from outside the United States.
     

Summary of this topic

Click the gray button for ten key points to understand about laser pointer use during protests.

Why lasers are used at protests

Lasers are used at protests for various purposes:

  • Aiming at authorities to distract or temporarily flashblind them. This might be done to disrupt the authorities' view of the people in front of them (e.g., those holding the lasers). Or it could be more planned, as a diversion to draw authorities' attention from another area of the protest.

  • Aiming at camera sensors to temporarily flashblind, or permanently disable cameras. This was done in the August 2019 Hong Kong protests to try and shut down facial recognition systems used against protesters.

  • Aiming at buildings, helicopters, crowds, etc. to gain attention. This is the visual equivalent of shouting or chanting. There is no intent to harm or do anything other than to express displeasure against a target such as a police station, or to gain attention for the protest. (Of course, aiming lasers at people and aircraft is potentially hazardous and thus may have unintended consequences.)

  • Aiming at authorities to try to inflict eye or skin injuries. Powerful handheld lasers may cause eye injuries at close range. However, serious or permanent injuries do not generally occur for reasons discussed elsewhere on this page. (Be wary of any official accounts of eye injuries. They may not be accurate unless the patient has been assessed by an expert with experience in laser eye injuries.) As for skin injuries, usually handheld lasers are not powerful enough to injure uncooperative persons' bare skin at any reasonable distance. Also, the person will feel the heat build up and should be able to move or turn away before any significant burn occurs.

How to defend against laser attacks

Authorities can defend against lasers in a number of ways:

  • Persons directly illuminated by laser beams can blink, look down or look away. This reduces the amount of time the laser is in the eye and thus reduces any heat buildup. (Injuries from visible laser light are possible when the eye's lens focuses the light onto the retina. Whether an actual injury occurs depends on the power of the laser and the length of time it is in any one place on the retina. Also, by looking away, if there is an injury it would not be in the center of the visual field which is most important for good vision.)
  • Helmet shields can be equipped with tinted laser-absorbing strips that reduce the laser's brightness. Standard strips are effective against the most common laser colors used at protests, such as green at 532 nm and blue/violet at 445 nm. Custom strips can be made to protect against additional wavelengths. An advantage of the strip is that the wearer just tilts his or her head down so they are looking out the strip. Nothing needs to be put on as is the case with glasses. Photos and a description of such a laser-absorbing strip are at a news story here. One source for the strip is Laser Optical Engineering Ltd. in the U.K. Pricing is £25 (USD $32) per strip in low quantities (<200). According to the manufacturer, in field use it was found that direct attacks on police "stopped quickly" once protesters knew their lasers were ineffective and that laser attackers would be identified and arrested. A similar strip of protective film, 1" x 9", is sold for USD $25 by Kentek. In October 2020, Colorado company Super Seer announced their Lazer-Shield strip. Other companies which sell laser protective eyewear may have their own versions.
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  • Laser glare protection eyewear may be used by pilots or others facing constant laser harassment, who need to protect a full visual field (not just a strip). Some police air services and demonstration officers have been issued such anti-laser glasses. For example, Laser Optical Engineering Ltd. makes anti-dazzle glasses for police use. Pricing is £50 (USD $64) each in low quantities (<50). A July 10 2020 sole-source contract saw the Federal Protection Service buying Stingerhawk FT-2 Laser Protective Eyewear from Revision Military. The contract's expected cost was $125 for each pair, in quantity of 1,000 pairs. Additional companies that make anti-laser glasses are listed on this page which is about pilot eyewear; these companies also make eyewear for protection at protests.
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The Stingerhawk FT-2 Laser Protective Basic Kit includes glasses which protect against green lasers at 532 nm, blue lasers at 445 nm, and violet lasers at 405 nm. The Optical Density is OD4 at each wavelength, meaning it reduces the laser intensity by a factor of 10,000. The kit costs $200 in single quantity for civilian purchasers.

According to the
contract document, this is why FPS authorized sole-source purchasing of 1,000 Stingerhawk FT-2 glasses: "While several manufacturers make lenses that defeat the effects of these lasers specifically designed for Law Enforcement and aviators; the Revision FT-2 Laser Protective Eyewear model provides a broader laser protection to include protection from Green, Blue and Violet laser light. The FT-2 has adequate visible light transmission and FPS has also had reports of violet laser use during these demonstrations creating the need for the broader protection. Revision Hawk was the provider of the rest of FPS head gear; therefore, the Revision Hawk Stingerhawk FT-2 Eyewear is made to to works with the helmets that FPS utilizes. The Stingerhawk FT-2 Laser Protective Eyewear provide the needed protection for the laser wavelength of concern, the feature wrap around protection and ballistic protection required for law enforcement operations. Market Research shows that there are no distributors of the lens; they are only available from the manufacturer."
  • Laser-wielding demonstrators generally can be easily identified. The visible laser beam points right back to the person holding it. Police can counter in real-time (arrest) or can use photos/video to later try to apprehend laser attackers.

  • Police can use bright light as well. In the August 2019 protests, the Hong Kong Journalists' Association accused police of aiming "strong flashlights" at journalists to obstruct their reporting.
   
Authorities can also ban lasers during demonstrations and protests, as Los Angeles did in November 2020. While this may not stop persons from bringing or using lasers, it does give authority to arrest anyone with a laser, removing them from the scene.

Lasers at protests are unlikely to cause eye injuries

Photos of massed laser beams aimed at police, like the one at the top of the page, can be dramatic. But how effective are lasers in protests?

In terms of causing eye injuries to police, in general lasers are not effective. Even if a person wanted to cause an injury, it is hard to do so by handholding a low-power laser beam on an uncooperative person many yards or meters away who can close his or her eyes, or who can simply look away.

Authorities or the press may try to indicate these are dangerous weapons. During the August 2019 Hong Kong protests, police held a press conference where they showed a laser at a close range (roughly 20 inches or 1/2 meter) being steadily aimed at a motionless sheet of newspaper:



After a few seconds of being held on a dark (light-absorbing) part of the newspaper, smoke appeared:



However, in real-world protest conditions it is much less likely the laser could burn the paper. At longer distances such as from a protester to a police officer it is harder to keep the laser on a single spot so that heat builds up. The target can blink or move. The beam spreads as it travels, lessening the light energy density (a larger beam "dot").

To counteract the police claims, a protester held up a newspaper while dozens of lasers tried to burn it — "without success" according to a news story.



This is not to say that laser light is completely safe, or that it should be deliberately aimed at anyone's head. Ordinary citizens, police, and other non-laser experts should never deliberately aim a laser at a person's head or eyes. The risk of injury depends on many factors, such as the laser power, divergence (beam spread), distance, steadiness, etc. Because non-experts cannot fully evaluate the risk, it is safest and most humane to keep a laser beam well away from anyone's head and eyes.

Hong Kong police did claim potential injuries. They said "three of our officers received medical treatment after protesters shined laser guns at them." The nature of any injury was not reported.

In mid-July 2020, there were claims of potentially permanent eye injuries from protesters in Portland, Oregon. On July 21 2020, a U.S. Federal Protective Service spokesperson said "We have three officers who currently have eye injuries and they may not recover sight in those eyes from those laser attacks". The assertion was widely repeated by officials and the press. But it appears to be untrue. On August 4 2020 a federal official testified that there were 113 eye injuries during the Portland protests — none permanent: "We've had a number of officers who had days-long blindness. So far, they've all kind of come back, if you will." If there had been serious, permanent eye injuries they would have been mentioned during the official's testimony.

There is a report of a serious eye injury to a Los Angeles police officer during a routine call (not at a protest) in July 2020. The officer was targeted by a laser aimed from a fourth-floor apartment, apparently unrelated to the original call. He reported lost vision in his right eye, migraines and balance issues for at least two months after the attack. It is not known whether the injury would be permanent. Details are here.

Anyone illuminated by a laser who is concerned about eye injuries or aftereffects, should read the page "If you are hit by a laser beam."
   

Lasers can block or damage cameras

Laser pointers aimed at surveillance cameras can temporarily flashblind the camera, or can damage the sensor. The photo below shows flashlights (white on left side) and lasers (green in middle and right) being aimed towards a news camera. People near the lights are obscured. The one laser at right that is aimed most directly into the camera is blocking a view of many persons on the right side.



For blocking the view to be effective, the laser's light would need to stay on the camera lens. In most cases, as soon as the laser is taken away, the view returns.

If the laser is powerful enough, the sensor can be damaged. This may take the form of dark spots where the laser was brightest, or of horizontal or vertical lines where the laser damaged an entire row of pixels. Since the "injury" is localized, the rest of the camera sensor may continue to work.

Demonstrators cannot know whether a given camera is damaged and whether the damage renders the camera useless, unless they can somehow see its output.

Persons using cameras in an area where laser pointers are being used should take care. Damage can occur to still and video cameras, and even to smartphone sensors. A single direct hit from a powerful laser may permanently damage the sensor. If there is no physical shutter on the camera (as with smartphones and some mirrorless cameras), a direct laser beam can damage the sensor even if the camera is turned off. Journalists may wish to use lower-cost cameras to take photos or videos when laser beams are coming towards them. This avoids damaging expensive top-of-the-line equipment.

An important point is that camera sensors are more sensitive to bright light damage than the human retina. So the fact that a camera sensor was damaged does not automatically mean that an eye would also be injured by the same laser under the same conditions.

Lasers compared to knives as weapons

The graphic shown here describes general similarities between lasers and knives.
  • Both are useful tools which can become weapons when used with ill intent.
  • Both come in many different types, which can have very different damage potential.

For example, low-powered pointers are safe for household use by adults, while higher powered handheld lasers should only be handled by someone knowledgeable and cautious about their danger.

Knifes cause much more harm than lasers

However, there are also significant differences between lasers and knives as weapons.

As the text at the bottom of the graphic indicates, knives are much, much more hazardous than lasers.

For one thing, laser safety distances such as the NOHD are usually very conservative. Laser beams do spread out with distance; this reduces the energy in any one area. For this reason, noticeable or significant injury does not occur until much closer to the laser device than the conservative, "safe" distance.

For another thing, it is usually easier to defend against a laser attack. A person can close their eyes or look away to reduce or eliminate any harmful eye injuries.

About the pictures

The lasers pictured in the graphic give a general idea of the output. But note that a single type of laser such as the "Laser 303" shown for the 500 mW illustration, can come in powers from 10 to 1000 mW. For this reason, don't use the illustrations to determine the power of a laser you might have.

Also, the information printed on a laser about its power output may be wildly inaccurate.

Police and the press should be especially aware that the information printed on a laser device may be inaccurate.
     

Additional topics and information

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