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ArcticMyst Security by Avery

How I almost lost my vision...

Trevor

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...because of someone else. Even if you consider someone to be laser-safety-conscious; if they are not a laserist, they just don't know.

When I went home for Thanksgiving this year, it was the first time my Optotronics 150+ mW pen came home. My dad saw it, and was really impressed with it. Whoever you are, seeing one of these lightsticks at night is really cool.

Of our family, I'm fittingly the most laser-conscious, with my father coming in next. He volunteers for a service that broadcasts newspaper and books over radio for the print-handicapped; he often works with people who have heavily impaired or no eyesight. Everyone else in my family is irrelevant; I learned fairly quickly not to let them touch my lasers. :tsk:

I believe it was snowing outside, and I had been messing with my laser on our front porch. When I went back inside, he asked to see it. Given how conscious he is about eye-safety, and that I had briefed him about being very careful what sort of surface he shines it at, I let him. He messed about with it on the carpet for a few seconds, then proceeds to shine it at a pane of glass in a nearby door. Inches from my right eye, a visible green laser beam passes by my face.

I flipped out. That could have ended in disaster, and impaired vision in one of my eyes. I now have much stricter policies on the conditions in which someone else can even see one of my lasers, and much stricter policies on who gets to touch or use them. Simply is not worth the risk.

I think it boils down to what a laser is - it's a beam of light. Everyone can respect a handgun or a knife, everyone knows what they're used for and what they can do. But very few people have ever seen enough photons in one place to cause damage; therefore, the vast majority of people just do not respect lasers like we do.

I believe we can all take a lesson from Aretha...



Hope someone benefits from my experience.

-Trevor
 
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wow, close call! I caught a reflected 300mW 660nm beam in my left eye because of a very similar situation. Luckily I did not receive any permanent damage.
 

Ears and Eggs

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Damn, glad to hear that you are alright. Seems almost everyone on here has a story of how some untrained laserist almost cost them their vision. It's happened to me before, once with nearly disastrous results. I went with one of my friends to visit a small group of his friends at their apartment. One of them was smoking and there was smoke in the air so I showed them some cool effects from my 150mW CNI greenie. Naturally everyone wants to try it, so I give them all the safety speech and light a match to show how powerful and potentially dangerous it is. The first few people take it and carefully point it into the air to see the beam. Then the second last person takes it, shines it onto the TV, blowing out several pixels on their 40" LCD TV, then shines into onto a silver sculpture, showering the room in beams. We quickly grab it from him and I put it away for good. Thank God all our eyes were uninjured. Funny thing is that less than a week later, the same guy got the whole group evicted from their apartment after spending all the rent on crack, punching a hole through the wall and throwing a boom box at the landlord in a stairwell.
 

Asherz

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I believe the reflection of light relative to an air/glass interface is only 4% assuming the angle of incidence is below the critical angle of internal reflection, meaning only 6mW of light would be reflected into your eye if we are assuming your laser is on spec and the plane of glass is perfectly flat.

From what I can make out by your post you were saying that the reflection of the beam was close to hitting you? If so I doubt it would have done any damage to your eye, not to say that laser safety should not be taken seriously with reflective surfaces though.

If you are talking about direct exposure to the beam I apologize, and agree you could have been hurt :(
 
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Your lucky nothing bad happened.

This is the one thing that sucks about owning a high powered laser.
We love them, and are amazed at their beauty. This makes us want to show and share them with people. When people do see them, they insist on trying it for them selves.
You have to decide to either be a dick and say no. Or tell them the rules and hope they don't decide to do something stupid. Or just buy a boat load of safety goggles for everyone to wear.

I live in a duplex, I have a front yard but no backyard. I used to have fun with them out in front all the time. I don't anymore unless it's really late.
I got tired of the neighbors kids or other people passing by, stopping and asking to see them.
 
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Glad to hear you are alright, twhite828.

Seems almost everyone on here has a story of how some untrained laserist almost cost them their vision.

I had an identical episode with my father! (and grandmother too :whistle:) I actually told them both about dangers... but guess they forgot everything I said as soon as they pushed the button :cool:
 

Benm

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I believe the reflection of light relative to an air/glass interface is only 4% assuming the angle of incidence is below the critical angle of internal reflection, meaning only 6mW of light would be reflected into your eye if we are assuming your laser is on spec and the plane of glass is perfectly flat.

You're right on that - 4% is the typical figure for a normal angle ('head on') hit, it can be slightly more if the angle is more shallow... but considering the scenario it probably was pretty close to head on.

Its still a situation to avoid, but in all reality chances of getting any permanent eye damage in this story were limited.

Then again, people not used to handling lasers somehow seem to be able to do something dangerous no matter what. On the positive side, some how this can be very educational, such as the act of setting ones own pants on fire ;p
 

Asherz

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You're right on that - 4% is the typical figure for a normal angle ('head on') hit, it can be slightly more if the angle is more shallow... but considering the scenario it probably was pretty close to head on.

Nice to know I got the right figures, it's been a while since I did this in school :)
 
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I once got the reflection from my 200mW o-like in my eye after I dropped it, I bent down to pick it up off my bed, my glasses fell off and the reflection from my window got in my eye. I was freaking out for a bit, I'm always more careful now.

will
 

Trevor

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Its still a situation to avoid, but in all reality chances of getting any permanent eye damage in this story were limited.

Oddly enough, this is the only green I own, so I have no idea how to gauge power based on beam visibility.

I just flipped because I saw a visible beam go by me.

Perhaps I should acquire a 5mW greenie...

-Trevor
 
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The 4% mentioned here is correct for a air-glass surface, but a glass is usually very thin, and a glass-air surface soon follows, adding another 4%, making about 8%. This only gets worse at angles, any angle. And there's no critical angle when entering a medium with a higher refractive index, only the other way around.
But at angles the polarisation also comes into play, but unless you manage to hit the brewster angle with the right polarization, assume it's worse than 8% reflecting.
 

jwc

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My pistol coach has three basic safety rules:
1. Always point the gun in a safe direction.
2. Treat the gun as though it was loaded.
3. Keep your finger off the trigger until you are ready to shoot.

It certainly seems like these rules also apply to lasers.
 
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I had a similar story my friend was pointing it in my ear and I turned my head and caught a direct beam from my 50mw green:cryyy: it made me super scared but I think im fine!!!
 

Trevor

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My pistol coach has three basic safety rules:
1. Always point the gun in a safe direction.
2. Treat the gun as though it was loaded.
3. Keep your finger off the trigger until you are ready to shoot.

It certainly seems like these rules also apply to lasers.

4. Don't point it at anything you don't want obliterated. ;)

-Trevor
 
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I've had some experiences much like what you described here, I totally agree people
are ignorant to lasers being able to cause damage to things. The only person I truly trust is my best friend, we're both laserists and I could trust him with my life, even more so my vision. So ya, we do some risky things with these things, but trust is everything, if I didn't trust him and moved quickly thinking I was in danger i'd end up putting myself in danger.
 




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