Lasers safe to bystanders in the path of beam?

[ChaosTheory]

Are laser rangefinders harmless to a bystander who might get the beam in his eyes? I was thinking about what would happen if PGA caddies used them. Shooting a flag on a green that is ringed by spectators, someone would be in the line of fire. The same thing applies for the rest of us when there is a group on the green with the flag pulled, and someone in the fairway shoots off one of the people in lieu of the absent flag.

 

So, wondering if this is a non-issue?

[Hateto3Putt]

Since there have been no lawsuits, it's a non issue.

[wfwp]

https://www.aao.org/eye-health/news/laser-pointer-eye-injury

 

This article has good information. The laser rangefinders I have used have a clear warning not to use in the direction of people.

[ThinkingPlus]

The lasers used in laser rangefinders are eyesafe. While it is never recommended that you look into any laser at close range while it is on, the lasers used in laser rangefinders will not cause eye damage if you did. At any kind of range where bystanders would be located it is also clearly a non-issue. In general the public is not allowed to purchase or own a non-eyesafe laser. Certain licenses are required that are typically only available to businesses or the government.

 

As an aside, the lasers used typically have a wavelength of ~1.5 microns which is invisible. They are pulsed lasers with pulse energies in handfuls of microjoules. The beam of light diverges a good bit as it leaves the rangefinder further reducing the energy that would reach your eye. There is an ANSI-Z (don't know the exact doc number) document which outlines in great detail what does and does not constitute an eyesafe laser and provides laser classifications (Class I, II, IIIR, IIIA, IIIB, and IV - I think that is all).

 

Edit: Corrected energy units.

[Socrates]

The lasers used in laser rangefinders are eyesafe. While it is never recommended that you look into any laser at close range while it is on, the lasers used in laser rangefinders will not cause eye damage if you did. At any kind of range where bystanders would be located it is also clearly a non-issue. In general the public is not allowed to purchase or own a non-eyesafe laser. Certain licenses are required that are typically only available to businesses or the government.

 

As an aside, the lasers used typically have a wavelength of ~1.5 microns which is invisible. They are pulsed lasers with pulse energies in handfuls of microjoules. The beam of light diverges a good bit as it leaves the rangefinder further reducing the energy that would reach your eye. There is an ANSI-Z (don't know the exact doc number) document which outlines in great detail what does and does not constitute an eyesafe laser and provides laser classifications (Class I, II, IIIR, IIIA, IIIB, and IV - I think that is all).

 

Edit: Corrected energy units.

Bushnell lasers are rated at <0.5 mW which is way below the 5 mW of laser pointers which are dangerous. From the linked article: If a laser with less than five milliwatts of output power is directed at someone's eye, that person can blink or turn away without suffering an eye injury...

 

I think we are fairly safe in not being concerned.

[ThinkingPlus]

The lasers used in laser rangefinders are eyesafe. While it is never recommended that you look into any laser at close range while it is on, the lasers used in laser rangefinders will not cause eye damage if you did. At any kind of range where bystanders would be located it is also clearly a non-issue. In general the public is not allowed to purchase or own a non-eyesafe laser. Certain licenses are required that are typically only available to businesses or the government.

 

As an aside, the lasers used typically have a wavelength of ~1.5 microns which is invisible. They are pulsed lasers with pulse energies in handfuls of microjoules. The beam of light diverges a good bit as it leaves the rangefinder further reducing the energy that would reach your eye. There is an ANSI-Z (don't know the exact doc number) document which outlines in great detail what does and does not constitute an eyesafe laser and provides laser classifications (Class I, II, IIIR, IIIA, IIIB, and IV - I think that is all).

 

Edit: Corrected energy units.

Bushnell lasers are rated at <0.5 mW which is way below the 5 mW of laser pointers which are dangerous. From the linked article: If a laser with less than five milliwatts of output power is directed at someone's eye, that person can blink or turn away without suffering an eye injury...

 

I think we are fairly safe in not being concerned.

Sort of like comparing apples and oranges. Lasers used in rangefinders are pulsed, invisible lasers. Lasers in laser pointers are CW (continuous wave), visible lasers. Blink response is part of the safety chain for visible eyesafe lasers. There can't be a blink response for the invisible lasers in rangefinders. The low pulse energy and the insensitivity of the eye to the ~1.5 micron wavelegth makes the rangefinder laser eyesafe.