Laser Visuals Research are saddened to learn of an incident in Russia where it seems the laser used at an event has caused around 30 people in the audience to suffer damage to their eyesight. It would appear from reports on SkyNews and several UK national newspapers that guests at the Aquamarine Open Air Festival in Kirzhach, Russia began seeking medical attention in the days following the show, complaining of vision problems. Russian health officials have confirmed that some of those affected have lost up to 80 percent of their vision.

Exact details are a bit sketchy and it is not known who performed the laser show, but mobile phone footage from the event would suggest that the laser used was a Class 4, high power pulsed laser, and it was the fact that this laser was pointing into the faces of the guests that has caused so many injuries. Reports suggest that due to the rainy weather conditions this laser was originally intended to be used outdoors but instead ended up being used undercover.

From what we know it looks to be a severe case of operator incompetence, and lack of planning and understanding of the hazards and their consequences.

Are Pulsed Lasers safe to look at?

Pulsed lasers produce an output that has a much higher peak power than regular Class 4 CW lasers. These peaks in each pulse, although very short, contain enough energy to be harmful when viewed directly, even over a long distance. Pulsed output lasers should only ever be used in safe environments such as large arenas and outdoor spaces, where the beams have enough space to be directed safely away from the audience, can terminate safely. Under no circumstances should they ever be pointed at people's faces. As long as the appropriate precautions are taken by the operator, who must ensure that the laser light from these types of devices does not make contact with people's faces, then viewing such shows can be perfectly safe.

What about other Class 4 lasers?

A Class 4 laser is any laser device that produces an output of 500mW (0.5W) or more. There is no upper limit to this classification of laser. The internationally accepted Laser Safety Standards warn that this type of laser can be damaging to both eyesight and under some circumstances skin. Laser lightshows use this type of laser because the beams and effects need to be visible and look intense. Pointing such lasers over the heads of the audience is normally the safest way to view a Lasershow . Pointing such Class 4 lasers directly at an audience can be safe as long as the laser effects distribute the laser energy appropriately. This can be achieved by making sure that there is enough separation distance, the laser is appropriately diverged (spread out), and that the exposure times are limited to what is known to be safe.

Could this happen in the UK ?

The use of lasers at venues is covered by general UK Health and Safety legislation which is designed to help protect both the workers and members of the public alike. Local Authorities recognise that the lasers used for displays and shows are potentially hazardous and in this regard venues will also normally have entertainment licence obligations relating to the use of lasers that they should be working to.

Through our own work as independent laser safety consultants to some of the UK 's leading entertainment venues we regularly get to see a wide range of laser installations. And like nearly every other business sector, some are good, and some are not so good. There have been instances in the last year with pulsed lasers similar to that used in Russia being pointed over the audiences of major tours. This in itself is not hazardous. However the fact we saw these lasers being used without there being any physical masking plate at the bottom of the output windows, it would have been quite foreseeable under a number of different circumstances for the pulsed beam to make contact with the audience.

I've heard that lasers can damage cameras and video projectors, is this true?

There have been several reported instances of Class 4 lasers having been used at events in the UK and abroad where the beams have accidentally struck a camera lens and damaged the CCD sensor array, or hit a video projector lens and damaged part of the projection system. There is growing awareness of this kind of occurrence among equipment owners and often they will take protective action to reduce the chances of costly equipment damage, such as covering the lenses when the lasers are being set up etc. Users of any Class 4 lasers should be assessing the risks and identifying these types of hazards, and taking appropriate measures not to damage other equipment because of a laser beam strike.

How can I stop any accidents happening in my venue?

Fortunately reports of accidents have so far been fairly rare, and we hope it continues to stay that way. But rapid advances in technology are meaning that higher power lasers are appearing more and more, and are able to be placed closer to the audience and at closer separation distances. The BBC news site (http://news.bbc.co.uk/1/hi/health/3644358.stm) carries a story where these concerns are mentioned by one of the UK government organisations. Many such accidents and occurrences are entirely avoidable if the laser system in use is installed and operated with proper planning and forethought, by competent and skilled operators. One of the first things to check is to see if the supplier can provide appropriate evidence of insurance details, and what laser training their operators have. You should also be able to ask for a method statement and risk assessment for the work that is intended to be carried out. The Health and Safety Executive (HSE) has published guidance (HSG95) on how Lasershow s can be operated safely. The British Standards Institute has also recently published its own guidance document PD IEC/TR 60825-3:2008 Safety of Laser Products: Guidance for Laser Displays and Shows.

If the laser installer/operator is able to demonstrate compliance with these guidance documents it is unlikely that the audience or fellow workers will be exposed to any harmful laser radiation.

Will the people at the Russian event's eyesight return to normal?

Without knowing the exact nature of the injuries it is difficult to comment. We would hope for the sake of the injured people that they do recover as much as is possible. Based on past medical recorded instances of laser eye injuries, the chances of making a full recovery may be doubtful. When the delicate tissue on the inside of the eye known as the retina, gets damaged, the scar tissue that grows back does not have the same cell structure making up the light receptors that a normal undamaged part of the retina has. This can lead to blind spots appearing in the vision. How much vision is affected and how noticeable it is depends on the extent of the injury and at what part of the retina the injuries occur. Over time, the subjects are likely to get used to the defects, and most probably not notice the damage so much.