Saftey Range for 50mW Green

[xJumper]

Ok so what is the average range a person must be at before a 50mW Green laser cannot damage their eyes?

 

[chido]

Just don't point it directly at someones eyes.

 

[Razako]

It depends on the divergence of the laser.

 

[charleytown55il]

how about if it has a divergence of1.2 mrad?

 

[xJumper]

Ok now don't get to technical! First off im not going to point it as somebody's eyes but I just want to know, just a general average for most 50mW green lasers.

 

[Benm]

Its a bit of a complicated thing to answer really. The theory is that a 5 mW or less beam entering the pupil entirely would do no damage in practice because you blink fast enough.

So for a 50 mW only 1/10th of the beam can safely enter the eye, at a pupil of 7 mm diameter that would equate to a spot about an inch in diameter. At 1.2 mrad that's equivalent to 20 meters or so for a typical green laserpointers beam.

But all of this is just a calculation and you should really avoid anyone looking directly into a laser. I doubt it will do any serious damage at 20 meters or more provided that the subject has a normal blink reflex and pupil size - but this is NOT something to be tested.

 

[xJumper]

Ok thanks for the anser, I was just wondering because in my city I shoot the laser to roof tops to see how far it can go and since I have a map I can than mesure the distance and maybe if somehow sombody got hit in the eye 1 click away he might get eye damage.

But dont worry I wont be pointing this into anybodyes eyes!