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Thread: Protective eyewear , where do I get it?

  1. #1

    Default Protective eyewear , where do I get it?

    Where can I get a couple pair of green laser goggles?

    I'd like some that are comfortable.

    Are they specific to wavelength or are there universal goggles?

    Do they dim the beam?

    Are the eyeglass style OK?

    What can I expect to spend?

    Thanks I'm new and already half deaf don't wanna try blind

    Ryan

  2. #2
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    Check E-bay.......seen a few floating on there for around 80.00. If you need them very soon www.mfgcn.com [Axiz laser] sp? has them for around a $100. They are @6.5 O.D. @532nm. That will save reflections and accidents from your eyes. Get the highest optical density you can afford for the wavelength of the laser you are using. You only have one set of eyes. Horror stories abound on the web. Better safe than seeing with vision that resembles a poster board that has been shot with a shotgun. :!:
    You are the only one that can make your dreams come true....and the only one that can stop them...A.M. Dietrich

  3. #3
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    Default Re: Protective eyewear , where do I get it?

    Quote Originally Posted by pietruk
    Where can I get a couple pair of green laser goggles?
    Like Mecheng3 said - have a look on E-bay first. (Search for laser goggles and you'll get a bunch...) Broadband argon goggles will protect you from 532 nm light, but probably will not block any leaking infra-red that might be leaking out of your DPSS laser. If you go with Argon goggles, make sure your DPSS isn't leaking IR.

    Are they specific to wavelength or are there universal goggles?
    Yes, they are specific to either a narrow band of wavelenths, or more commonly to a wider band of wavelengths. For example, you can get protection for red lasers that will cover the relatively narrow band between the 632.8 nm of a HeNe and the 650nm of a direct injection diode laser.

    More common are broadband Argon goggles, which are usually good from 514 nm all the way to 456 nm or better. (Though the actual optical density rating at different wavelengths will be slightly different... Check the spec sheet.)

    But the goggles that work for argon are useless for protection from a hene laser, and likewise the hene goggles won't protect you against the beam from an argon or a DPSS laser.

    Do they dim the beam?
    Yes. They make the beam itself very hard to see in air. You can see the spot reflected on the wall, but the beam itself will be reduced in apparent brightness to the point that you probably won't see it. (If you think about it, this makes perfect sense. The goggles are attentuating the light at the frequency the laser is operating at, so the beam will be hard to see.)

    Are the eyeglass style OK?
    Yes, so long as they have side-shields and/or cups such that your whole eye is protected.

    What can I expect to spend?
    Anywhere from $20 to $50 for a pair off E-bay. $100 and up if you buy them retail. For the most part, the more expensive ones are more comfortable and offer better protection, and are more consistent across the wavelengths they protect against.

    Adam

  4. #4

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    What is the number designation at various wavelengths represent?

    Is there an optimal or minimum rating?

    Doesn't not being able to see the beam take some of the fun out of it?

    Can eye damage be caused by looking at the beam or do you need to get flashed directly?

    Thanks again

  5. #5
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    Quote Originally Posted by pietruk
    What is the number designation at various wavelengths represent?
    Goggles are rated using a logarithmic scale. You should see an optical density number listed for each wavelength. A pair of goggles with OD3 rating will reduce the power of the light by a factor of 1000 at the specified wavelength. OD 6 lenses will reduce the power by a factor of one million.

    I've seen goggles with an OD 16 rating... That would reduce the power by a factor of 10,000,000,000,000,000. (That's 10 thousand trillion!)

    Is there an optimal or minimum rating?
    It depends on the power of the laser you have. The idea is to reduce the power of the beam so that if it strikes the goggles, the amount of light that enters your eye is low enough that it won't cause you any harm.

    As a bare minimum, you need goggles that will take the power output down below 1 mw. So, if you have a class IIIb laser that puts out - say, 200 mw, then the MINIMUM level of protection would be OD 3. But most people like having a safety factor, so they might go for OD 4 or more.

    Doesn't not being able to see the beam take some of the fun out of it?
    Once you have your laser projector all put together and working correctly, you can remove the goggles and watch the show. But while you are assembling all the parts, aligning the galvos, adjusting the mirrors, tweaking the galvo amps, etc, you want to wear the goggles so that if something goes wrong, you are protected. The goggles should be worn whenever you are messing around with the layout of the projector and the laser is on. (If you need to work without goggles, make sure the laser is disconnected from it's power supply!)

    No one wears their goggles all the time. You are right, it would take all the fun out of it! But until everything is working 100% and you KNOW that you are in a safe area, you should wear the goggles.

    Can eye damage be caused by looking at the beam or do you need to get flashed directly?
    Under most cases, looking at the beam as it is scattered by the dust or fog in the air is not going to cause a problem. It's only when the beam enters the eye directly that you have a problem.

    However, if you have a VERY high power laser (many watts) it can be painful to look at the beam if a blast from the fog machine suddenly makes the beam reflect more light in your direction. But this is normally only an issue with outdoor shows.

    Adam

  6. #6
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    my leadlight (modded, maybe 30\60mW) did reflect from the mirror and directly into my eye :? i guess the distance was 3-4 meeters.

    The flash was so bright that the world did stop in my head for a blink of a second...
    after that i did not notice anything strange.
    But after 2-3 hours i notice a tiny tiny white spot on my eye, I did notice it very well everytime i used my computer... it was a DAMN annoying white spot following my eye movment.

    But after some days maybe 2weeks it was all gone.
    And now i can`t se it, at all, so i guess and HOPE it`s gone forever :roll:


    But after that i did pay more attention to the careful use of the laser pointers...

  7. #7
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    Liteglow:

    Congratulations... You've experienced flash-blindness!

    Lucky for you it appears you didn't do any permanent damage to your retina, but you really can't be certain because the human brain is *really* good at combining information from both eyes to "fill in" blind spots. (We all have a large blind spot in each eye where the optic nerve attaches to the retina, yet you'll never notice it unless you try a special test like this that makes it noticable.)

    Sometimes the effects of flash-blindness only last a few minutes, but other times they can persist for days or even weeks.

    Adam

  8. #8

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    I've read that the US gove rates 30mW as the danger threshold and I'e seen people say thats high.

    I've seen it stated that 20mW will not cause permanent damage from flash blindness and it would appear that the FDA thinks 5mW is that threshold.

    I am not suggesting that anyone be careless with a laser. I am trying to clairfy what I've seen.

    Thanks

  9. #9
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    pietruk;

    You are confusing the threshold for damage to occur to the eye with the threshold for safety and pain. There is a difference!

    It has been proven that under normal circumstances 5 mw or less will not cause lasting damage to the eye. That is not to say that you WANT 5 mw in your eye when you are working on your equipment. (Bright light *hurts*....)

    Flash blindness is almost never permanent, but it can be very annoying while you wait for the effects to go away. 30 mw will most definitely give you flash blindness, though it probably won't be permanent. (I've known people that have been flashed by 100 mw or greater and had no long lasting effects. However, they were very lucky.)

    All of this is secondary to the selection of a set of goggles, however. You aren't selecting the goggles to prevent permanent retina damage, you are selecting them to prevent ANY eye injury - even temporary flash blindness.

    Thus the less than 1mw minimum requirement. (And believe me - 1 mw is a LOT! You will have a bright spot in your field of vision for several seconds after a direct hit at that power level.)

    To put things in perspective - the most powerful DPSS laser I have puts out just over 100 mw, yet my goggles are rated for OD 6. Likewise, my most powerful HeNe is only capable of 14 mw, yet my HeNe goggles are OD 4. Trust me, you want the safety factor! You'll still be able to see the dot on the wall just fine. (Or on the mirror, or the diffraction grating, or whatever else you are working on.) The human eye is very sensitive, so even if you're down into the microwatts of power you'll still see it.

    Adam

  10. #10

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    I was aware of the pain/damage threshold difference. I just wanted to clarify the validity of the facts I'd seen on permanent damage thresholds.

    I'm no masochist, well not went it comes to eye pain.

    Thanks for clarifying

    Ryan

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