You get idiots shining Lasers up at ACFT and at car drivers on highways. Which while at altitude (distance) is probably not a problem because the beam is attenuated.
At close range High powered Laser beams focus on the retina and since it is coherent light it is a powerful localised hot spot that easily damages the retina even with natural blink reaction.
The Vic law states Lasers must be less than 1mw output. Class 1 and 2 Lasers are ok if they are under that 1mw. Class 3 and above are illegal unless controlled.
http://www.consumer.vic.gov.au/CA256902000FE154/Lookup/CAV_Publications_Product_Safety/$file/laserpointers.pdf
Here is some facts sheets from defence.
http://www.defence.gov.au/dpe/dhs/in...e_Exposure.pdf
A quick goggle shows a bucket load of Lasers for Astronomy at far greater than 1mw...even neodymium doped lasers that have ranges over 12,000 ft. Man this stuff is dangerous in the hands of the general unwashed. Still it's the IR Lasers that are more dangerous as they do not invoke a blink reaction...aka that's why the military use near IR Lasers.... also because of less atmospheric attenuation at those wave lengths.
I'm not saying the Astronomy crowd would behave irresponsibly but these are not safe. Although all that said i reckon 1mw class 2 Laser of 1mw is generally quite safe. The spawning of the Laser diodes have created a nightmare for Law makers.
I was SNCOIC of F18 FLIR LTDR Pod /Laser Lab and systems at Williytown for a number of years as well as the Base LSO (Laser safety officer) and SNCOIC of Pavetack mirror control Laser head overhauls..a few moons to many ago!