Laser Safety

We all enjoy a good knees up or party, and with the hundreds of events like concerts and open air festivals that are available to us up and down the country we are lucky enough to have access to such events and be bowled over by any number of fantastic firework displays or lighting effects found in stage shows and productions.
 Many open air events will use ' eye safe" lasers which are lasers that emit at far infrared wavelengths of light that are considered as safe for our use and enjoyment. They are also used for military purposes like targeting and long distance range finding.However a recent report on experiments that have been conducted that measured femtosecond pulses (a unit of time equal to 10−15th of a second) from far-infrared lasers now pose concerns that they may be accountable for breakages in exposed DNA strands.
 Obviously lasers need  to be regulated for use to protect the retina, as any intense focused light can cause burns. At wavelengths omitted by far-infrared lasers most of the light is "absorbed" by water found in the front of the eye thereby never reaching the sensitive tissue of the retinal area.

The concern comes from not just the threat of light , or heat from such lasers but damage induced from chemical changes.

DNA damage has been found to come from rotationally “hot” OH molecules formed in the strong optical fields of laser pulses at 1350 and 2200 nanometers. However, it remains to be shown whether these DNA-attacking hydroxyl radicals form at the lower powers found in commercial applications.