eye protection for powerful hand held laser pointer

Hi I've recently bought a reasonably powerful laser pointer and want to ask some specific questions about eye protection that haven't been asked in other threads.

Is it ok to point the beam at something that is over 100 meters away when not wearing any eye protection at all?

Can the light refract or reflect back into my eyes with enough power to cause damage from that distance?

Hypothetically if there is a lot of pollution in the air or if it was raining would it be bad to use the laser at all whilst outside because the entire beam is extremely visible and the light could be bouncing back into my eyes?

Sometimes I feel like my eyes are a bit stressed after using the laser for 5 minutes or so but only shining it on things that are quite far away and not looking directly at the beam too often. Im not sure if what im feeling in my eyes is psychological or not because it is quite a subtle feeling. However im well aware powerful laser pointers can cause serious eye damage when used without eye protection. Hence my asking these questions to figure out if there are ways of using a laser like this without causing any damage to the eys.

Thanks

Ideally one should wear eye protection just for accidents purposes. But at 100meters you should be ok.
What kind of laser are you speaking of?

As for the rain, I would be extra careful because of your lens. If any moisture were to get on the lens it could be detrimental to the laser.

Cheers

I didn't mean I was using it whilst standing in the rain just on a balcony under cover when its raining or something like that.

The laser just says "Laser 303" on it, i bought it in vietnam and paid about $30 USD for it. I cant give you much info on it because it didnt come with a box or anything. It has a key that is needed to engage the button (just has a single button on the top) and the battery it takes says;
AX 18650 4000mAh 3.7V li-ion

Often when im using it on a balcony the beam hits things for short moments that are probably only 20 meters away or less, could that cause damage over an extended time?

Im traveling at the moment and dont really have the option of buying safety goggles because im never at a particular address at any time.

Oh wow. I'm half Vietnamese

This laser is somewhere in the area of 100mw . You should be fine as long as a reflection doesn't directly hit close to your eyes. Make sure not to view the dot up close on reflective surfaces. Also even white surfaces will strain your eyes. As long as your careful and use caution when pointing , you should be ok. That is not to say at accidents can't happen, but that's the case with everything.

Vender said:

Hi I've recently bought a reasonably powerful laser pointer and want to ask some specific questions about eye protection that haven't been asked in other threads.

Is it ok to point the beam at something that is over 100 meters away when not wearing any eye protection at all?

Can the light refract or reflect back into my eyes with enough power to cause damage from that distance?

Hypothetically if there is a lot of pollution in the air or if it was raining would it be bad to use the laser at all whilst outside because the entire beam is extremely visible and the light could be bouncing back into my eyes?

Sometimes I feel like my eyes are a bit stressed after using the laser for 5 minutes or so but only shining it on things that are quite far away and not looking directly at the beam too often. Im not sure if what im feeling in my eyes is psychological or not because it is quite a subtle feeling. However im well aware powerful laser pointers can cause serious eye damage when used without eye protection. Hence my asking these questions to figure out if there are ways of using a laser like this without causing any damage to the eys.

Thanks

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Ah!
Safety.

Firstly , I commend you for asking.
Not many think of safety first when they get their hands on lasers.

Now .
Do you need eye protection for looking at reflected rays from objects 100m away?

Firstly , for a completely matte object . The diffuse reflection decrease by a million fold for every meter of distance travelled by the light under nominal conditions.
So theoretically, for a 1W laser , ignoring the effect of rayleigh scattering and the mumbo jumbo . Its going to be well under the MPE.

However, most certainly for the objects you encounter in real life. They won't be ideal black bodies or matte objects.

They'll be semi-reflective or even reflective objects. In that case , we can't say for sure without understanding the materials your laser struck on ,such as the surface conditions , the absorption spectrum , the coatings ,etc.
The source beam's divergence, wavelength , and more.

However, as a general rule of thumb , in excess of 50m ,striking a non-reflective surface. It Should® be ok.




For direct hits however.
Avoid AT ANY COST!





Secondly.
As for the pollution problem.
You are then talking about the suspended particulates being stuck by the photons and then bouncing back into your eye. I wouldn't lose sleep over it.
Unless its aluminium dust.
As for the smog , the laser has been sufficiently scattered for it to be not of major concern. However, it still poses as a glare hazard at close range. Nothing serious ,but just not particularly pleasant.




Thirdly.
The dizziness issue.
Well that's a bit harder to explain , but I personally out of my non-medically educated arse. Think its your brain being confused by the illuminance difference between the beam and the relatively darker background.
Although the background is dim ,there is an unnatural beam of light waving in front of your eye.
The brain perceive such discrepancy as signs towards poisoning and thus create the sense of dizziness and tendency to barf so as to "get rid of the ingested poisons".

Or that's my theory at least.
Not life threatening , you'll get used to it after your brain understand lasers won't poison them.

Could we maybe get a picture?

Im just curious to see what it looks like really :undecided:

Search 301 laser on eBay. You will see what they look like.

Alright, I see what we're talking about. Thanks T.

He said 303 not 301, the 303 comes in several powers up to 1000mw but if he paid about $30 then it must be the 100mw. A few people here on LPF have this same laser.

Alan

must have fallen out of the grid .
What is so special about the 303 laser?

EpicHam said:

must have fallen out of the grid .
What is so special about the 303 laser?

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As far as I know they are nothing special, in fact there are some threads here where people have had problems with them or had it quit on them.

Alan

Pi R Squared said:

As far as I know they are nothing special, in fact there are some threads here where people have had problems with them or had it quit on them.

Alan

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then.... why not just get a C6.
They've worked fine for all these years.
Not really much reason to go for 303 if you ask me.

1000mw 303 huh? I think your trusting the advertisement too much. Have you noticed they are 1000mw green.

Please search 303 1000mw laser

Tmack said:

1000mw 303 huh? I think your trusting the advertisement too much. Have you noticed they are 1000mw green.

Please search 303 1000mw laser

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EpicHam said:

then.... why not just get a C6.
They've worked fine for all these years.
Not really much reason to go for 303 if you ask me.

Click to expand...

I agree, the C6 is one of the best.

Tmack said:

1000mw 303 huh? I think your trusting the advertisement too much. Have you noticed they are 1000mw green.

Please search 303 1000mw laser

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I didn't really mean that I trust them, a green laser of that power should cost at least $1000. I am just saying many places are selling this laser at diferent prices and in claimed powers of 5mw, 100mw, 200mw, 500mw, 1000mw, but I don't trust any Chinese claims about lasers.

Alan