Questions on green laser IR danger

[Rob187]

I recently bought my first green laser and have been reading up on the laser section of CPF but can't find a straight answer to these questions:

What is the danger to your eyesight from the IR from an unfiltered green laser?

Isn't IR just E-M radiation with a longer wavelength than red?

How can a burst of IR damage your eyes more than a burst of green (or any other coloured light)?

Is the IR coming from green laser focused or is it a broad beam emitted light a normal flashlight beam?

Is the danger just that because IR can't be seen with the naked eye and therefore because your eyes won't blink, the IR light could shine into your eyes over an extended period causing damage?

Can someone help me here?

 

[comozo]

I recently bought my first green laser and have been reading up on the laser section of CPF but can't find a straight answer to these questions:

What is the danger to your eyesight from the IR from an unfiltered green laser?
None. caveat if you don't shine it directly or by reflection into your eyes

Isn't IR just E-M radiation with a longer wavelength than red?
Yup

How can a burst of IR damage your eyes more than a burst of green (or any other coloured light)?
At these wavelength's typically, no

Is the IR coming from green laser focused or is it a broad beam emitted light a normal flashlight beam?
broad beam compared to the green

Is the danger just that because IR can't be seen with the naked eye and therefore your eyes won't blink, the IR light could shine into your eyes over an extended period causing damage?
Yup

Can someone help me here?
Yes

***

 

[stephenmadpotato]

The subject of IR light damage is very VERY controversial. In my opinion, if you don't shine the laser within 10 feet of a person you should be fine. The IR light coming out of lasers is usually partially collimated. So it does extend farther then the green light, so if you shine the laser near a person, then IR light may be getting in their eyes and they have no clue.

 

[Rob187]

SMP - Thanks for your reply.

I still don't have answers for the majority of my questions.

Can anyone add anything or point me in the direction of a credible source?

 

[comozo]

What question were not answered ?

 

[Lighty]

What is the danger to your eyesight from the IR from an unfiltered green laser?

You talking intrabeam (directly in eye) or viewing diffuse reflections from a wall?

Isn't IR just E-M radiation with a longer wavelength than red?

Yes, it is outside the visible spectrum. Near IR is about 700nm to 1400nm.

How can a burst of IR damage your eyes more than a burst of green (or any other coloured light)?

IR is transmitted to the retina where damage can occur. The near IR is absorbed a little by the cornea, lens, eye fluid, and the retina.

This help or what do you want to understand more?

 

[comozo]

I still don't have answers for the majority of my questions.

Can anyone add anything or point me in the direction of a credible source?

There is no one particular source that can answer all of your questions the best all around source would be Sams laser faq second to that is keyword searches.

 

[Ashton]

I just wanted to point out two things.

Isn't IR just electromagnetic radiation...?

Everything is EMR, if you follow the energy spectrum it doesnt drop off, everything, heat cold, light dark, and even matter is part of the spectrum (though this is going off into quantum theory)

Also, the reason everyone HATES the IR in green lasers isn't so much because of hte danger, but because the IR confuses laserchecks and causes them to spitup a higher rating for the laser. Technically, the IR isn't the problem, it's the dishonesty of sellers who use that IR to inflate the rating of the lasers that pisses people off so much.

(NOTE: I did not say IR is harmless, it's dangerous too, more so than normal light because it's invisible!)

 

[Rob187]

Thanks for the replies. Much appreciated.

 

[VaThInK]

(NOTE: I did not say IR is harmless, it's dangerous too, more so than normal light because it's invisible!)

And not well collimated , which would disperse and loose it's optical power density very quickly after about 1 feet.