July 16, 2008 14:00GMT (10:00 AM U.S. EDT)
According to news reports beginning on July 14, lasers caused eye damage at the Aquamarine Open Air Festival, a rave near Moscow, Russia. At the July 5 event, "dozens of partygoers" reported eye injuries including partial vision loss. Digital camera and camcorder sensors were also damaged. The cause was reported to be due to a laser show originally intended to be pointed at the sky, which was instead aimed down into the audience due to rainy conditions.
The Aquamarine situation was an extraordinary event. Since laser shows started 40 years ago, there have been thousands of audience-scanning laser shows presented daily, with millions of enthralled viewers. In all this time, there have only been two reports of mass injuries; both were caused by misuse of a type of pulsed laser which should never be aimed at an audience.
Pulsed lasers confirmed
For this reason, ILDA initially suspected pulsed lasers were in use. Based on video of the event, this seems to be confirmed. Beam patterns on a wall show a dotted line instead of solid. This is characteristic of pulsed lasers which emit short, powerful bursts of light.
Pulsed lasers are fine for sky and overhead use, but they should NOT be used for audience scanning.1 This is because the pulses can pack 100 times the power of an equivalent continuous-wave laser which should be used instead. These emit a steady flow of light with constant power.
Injury-causing lasers far exceed safety standards
The Aquamarine lasers were being used irresponsibly and probably illegally. To cause such injuries, the audience exposure must have far exceeded agreed-upon international laser safety standards (IEC 60825-1 "Safety of Laser Products" and 60825-3 "Guidance for Laser Shows and Displays"). These standards cover aspects such as the beam intensity and scanning speed at the audience. Many countries have laws which are derived from these standards. Even in countries where there are no laser-specific laws and regulations, the IEC safety standards should be followed.
All ILDA Members are required to perform safe shows which follow the standards and their local laws. No ILDA Member was involved with the Aquamarine rave show.
ILDA's response and actions
First and foremost, our deepest thoughts and concerns go out to those who were injured.
ILDA was extremely distressed to hear about this incident. It appears that the lasers at this event were being used irresponsibly, haphazardly, not in accordance with international safety standards, and potentially illegally.
We have asked our Members for any additional information. At this time, we are only getting press reports. ILDA does not know the name of the laser company responsible for this, or any confirmed details about the laser equipment or usage.
Within a few hours of first hearing the news on July 14, ILDA's Board of Directors held a meeting via teleconference. They issued an initial statement based on the then-known facts. They also directed the ILDA Safety Committee to monitor the incident and to report on any changes in procedures or standards which may be necessary.
Laser shows are exciting for audiences. Being inside precisely-choreographed lightshapes is a wonderful experience. ILDA remains committed to safety first, and to having laser shows remain safe and pleasurable.
For additional information
Click to jump to:
How could this happen?
At this time, details remain sketchy. Some reports say that the lasers were originally intended for a sky or overhead show. But due to rain, the lasers were aimed downwards, under a tent, which put them into the audience. This type of pulsed laser NEVER should have been aimed into the crowd.
A few reports said the show was aimed at
the tent and light was "refracted" into the audience. This would have
been much safer. Unfortunately, the video shows the beams going directly
into the audience, so the refraction theory is not viable.
Who is responsible?
Under standard laser safety practices, the laser operator is responsible for the safe operation of the show. One or more operator is required to be onsite, monitoring the show, and turning off the laser immediately in case of any problem.
Even if promoters or audience members
re-aimed the pulsed laser from the sky into the audience, a laser
operator should have been aware of the hazard and should have stopped
the laser immediately.
I read that drugs may have caused the damage? Is this true?
A July 15 story in Kommersant, "Russia's Daily Online", says there could be other factors:
The fact that camera and camcorder sensors were damaged indicates that the lasers were far too powerful. Drugs may have made the eye damage worse, by widening the pupil (letting in more light) or by some other mechanism. But the primary cause appears from the video to be due to using the wrong type of laser for audience scanning.
They are not pleasant, but based on the
July 15 report, they are better than intially indicated. Retinal burns
are more permanent than retinal hemorrhages. One is a burn, the other is
similar to a bruise. The long term effects -- whether there is permanent
vision loss, whether it is in the center of vision or in peripheral
vision, etc. -- remain to be seen.
Why did the injured people wait a day or more to seek treatment?
In a rave situation, there is so much
stimulation and excitement that a person may not immediately recognize a
loss of vision. Or, their vision problems may be attributed to the
flashing stage lights, alcohol and/or drug usage, smoke in the air, etc.
Only later, when looking at a blue sky or uniform white wall, might
someone notice spots and seek treatment.
When I read about this online, there are a lot of different pictures of lasers, next to the stories. Are these all from the July 5 Aquamarine show?
As of July 16, almost all of these images are "stock photos" of laser shows. A few were from an earlier Aquamarine rave (in previous years). Please don't think that all these laser shows in the stock images are unsafe!
Is laser light some special type of light or radiation?
Visible laser light, like that used in laser shows, is like ordinary, conventional light from bulbs except more concentrated (coherent). Laser safety signs may say "Caution - Laser radiation". This refers to ordinary light radiation, like that from the sun or light bulbs or the flames of a fire. It is not the same as much-higher powered ionizing or nuclear radiation.
The eye can be damaged by bright
conventional light, such as staring into the sun or looking closely at
flashes from arc welders. Similarly, the eye can be damaged by bright
visible-wavelength laser light, if too much enters the eye and stays on
the retina for too long. The retina overheats and can be permanently
What makes laser light hazardous?
There are three main factors of laser danger: power, divergence and exposure time:
Laser pointers in the U.S. are supposed to be limited to 5 milliwatts in power. At this level, a person hit by the beam can blink within 1/4 second, without any effect from the beam.
The laser pointer in the Russian news video is above 5 mW. It has to be, in order to cause the burning bag. Also note that the laser pointer is close to the bag -- the beam divergence is very small at this distance. And note that the bag is black. This absorbs heat; a white bag would not burn.
You can't really compare a stationary
laser close to a thin black flammable surface, with a moving laser that
is much farther from the audience's eyes. A valid safety analysis of the
latter is more complex.
How do laserists make a safe show?
Doing safe laser shows means that the operator must be aware of the power, divergence and exposure time. They must use limited power, with a beam that is slightly "fat", and the beam should be kept moving. Any higher powers or static beams should be above the audience.
(Sometimes tricks are used, such as
having high powered beams above the audience which automatically dim
when they go into the audience. Because the audience is looking directly
at the dimmed beams, the overall brightness appears to be the same as
the overhead beams.)
Continuous vs. pulsed lasers
Lasers used in audience scanning shows should be continuous. This means the light is continuously emitted. Pulsed lasers can be extremely dangerous because they pack their output power into short bursts.1
It is the difference between someone putting their fist on your arm and pressing continuously, and if they pull back and put the same energy into one short punch (pulse). Your arm can take the continuous energy, but not the same amount in a short burst.
If you have a 40W argon (continuous) and a 40W Nd:YAG (pulsed), they both emit the same amount of energy. However, each 600 nanosecond YAG pulse has 70 times the energy as the argon's beam, during the pulse timespan. This means it is 70 times more hazardous. Said another way, the YAG appears to the eye as if it was a 2800W laser.
Industrial laser accidents vs. audience accidents
There have been eye damage accidents in laboratory or industrial settings. Usually the injured person is close to the laser output -- within a meter or two. The beam at this distance is very small and tight, such as a few millimeters in diameter.
For audience scanning shows, the audience is usually much farther away. The beam spreads out to the size of a coin or even larger. This helps lower the chance of injury, all other factors such as beam power being equal. This is why lab/industry accident rates cannot be extrapolated to audience situations.
ILDA Safety Panel Statement on Audience Scanning
Shows Safe and Enjoyable