Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers

How to Register on LPF | LPF Donations

Scratch on goggles

Joined
Nov 2, 2010
Messages
165
Points
28
Hello all.

Question about the lenses on most goggles. If they get scratched, are they still safe? Is the OD factor related to a coating on the lens, or is it usually embedded into the lens material?
 





Depends on what kind. If you've got high quality goggles like Eagle Pair, they are probably safe. If you have eBay $5 goggles they may or may not be.
 
I have a couple of OEM Laser Systems goggles, and a couple of LaserGlow goggles.

I believe both these companies are reputable?
 
Most tend to be of the same material, so a scratch would not matter. Eagle pair, OEM, are like that. Some goggles I'm sure have a coating instead.

Since you clearly have more than one pair on hand, consider doing a small "test" and seeing how the material reacts in a spot where it would not effect your vision.
 
If the diode "burns" (melts) easily the goggles (as black plastic of the same kind), then they absorb well it's wavelength.
I have $3 red goggles which i tested on a 405nm Sony SLD3235FV diode sold on ebay.
I have accidentally pointed the diode into my eyes through the goggles. I saw it like emitting tiny red spot despite it's an UV diode. When I look at reflected from non-fluorescent material beam, I can not see it.
My eyes did not get hurt, but I wasn't running the diode at it's full power. Actually it was 5 promiles PWM at 90mA, because I needed to look at the spot to focus it and it shoud not burn the matte plastic I used to focus at.
5 promiles = 0.005% ( Fpwm=2kHz, Tpwm=2000, Ton = 10 ).
 
Last edited:
I think in general it could be said that with goggles that block out a large part of the spectrum (say pass red, block green and red) the pigment is throughout the lens and a scratch will not reduce the optical blocking much.

In case it blocks a narrow wavelength range (such as blocks 532 but passes 500 and 600 nm) there could be a dielectric coating, and a scratch could remove that entirely. This would probably be visible though.

I've never seen goggles of the latter type, but i believe they do exist, probably for use in specialist applications where good color vision must be maintained (military etc).
 
I agree with the above (there's a typo... they block green and blue]). Moreover I've heard that there exist prototypes of goggles with several selective coatings - for the most common wavelengths of LASERs to protect the military pilots. But I have not heard about their prices.
My $3 glasses block the green and blue light and pass only the red. But this greatly reduces the color vision.
There's another problem: to focus the UV beam, I need to see the spot. So the red ones are inappropriate for this task. I do this at low power with a pair of "retired" yellowish sunglasses which employ polarization filter also. They do not block 100% of the 405nm (neither do my Polaroid sunglasses) so I can work.
 
Last edited:


Back
Top