Seem to remember posting two to three years ago on this subject,unfortunately being shot down in flames by someone with a little knowledge of lasers.
Like TheotherSimon as my avatar suggests I work on lasers. 30 years experience of which 18 years purely on medical lasers. At the moment on lasers for the treatment of diabetics. So in contact with most of the top guys in the field.
Pan retinal photocoagulation uses on standard lasers a power of around 120 -220mW at an exposure of 0.10S(edited wrong exposure time,not 0.01S,sorry) to achieve a blanching effect(dependent on pigmentation) inside the eye for diabetic retinopathy.This is a focussed beam at about 300-400 microns.
As TheotherSimon says and his maths is not wrong beam divergence at that distance comes into play,plus the 'blink reflex' of the eye is also a factor.
Not in any way condoning these idiots as it must be a distraction. Studies done at Dundee university after the spate of attacks on bus drivers concluded no permanent damge was done to the eye, and the distance between laser,drivers mirror and driver is a lot less than most of the 'air attacks'.
Last edited by lasernigel; 28th Oct 2008 at 10:27.