Lasers in the eye - Serious injury, Please Read

[yealf]

Hi there,
This year (2011) there were a huge number of lasers and laser pointers at burning man. At both the temple burn and the Isis high wire show on sunday, I witnessed some really unpleasant and potentially very dangerous behavior. People who were sitting were trying to shine laser pointers in the eyes of people who were standing in an attempt to bully them into sitting down.
Never mind that this is beyond obnoxious, I just spent the last half hour reading up on laser pointer eye injuries via google.
Here's the deal, up until the mid 90s laser pointers were very weak and harmless. Now many laser pointers bought from the internet are way, way stronger and fall outside any US regulation. They come directly from Russia and China. The green ones are the worst and probably will really mess up someone's eyes perminently . There were a ton of green ones at Burning Man. Red ones, any more than 0.25 seconds at 3 feet is potentially harmful. By the way it takes 0.25 seconds to kick in your blink reflex.
If anyone ever sticks a laser in my eye at Burning Man they will find themselves having to dig that fucking thing out of their ass at Reno Hospital.
Thanks,
Yealf.

[gyre]

A laser pointer makes a terrific target for pepper spray.

Just play along and respond.

[marck]

Just make sure the wind is playing on your side, and let the innocent bystanders be damned.

[marck]

What should also be mentioned is that anyone using lasers in that manner can, and should, be charged with aggravated assault, which is felonious in Nevada.

[Ugly Dougly]

Axes are legal to carry on BLM property. It's for firewood.

[trilobyte]

Giving this a nudge to the right forum.

[danielpower]

And the laser beam will cause permanent damage of eyes.

[Ugly Dougly]

Most laser pointers are unlikely to cause permanent eye damage, but since at Burning Man, you don't know what class of laser is pointed at you, and since it can be very distracting and potentially dangerous, the rule for lasers of all sorts should be:
DO NOT SHINE THAT IN ANYONE'S EYES.

It's kind of like taking a picture of someone without their permission.

[Mr.Coffee]

Most laser pointers are unlikely to cause permanent eye damage.

That is a blatantly untrue generalization. There are so many variables involved that you cannot predict what is going to happen, especially if you combine all of those variables with a chemically dilated pupil. There is a reason why it is getting harder and harder to purchase pointers - of any wavelength - with a power rating over 5mw. that has been deemed "safe" for use, but still not safe to shine in a persons eyes.

It is not uncommon to see laser pointers confiscated at music events, Especially events with laser shows, since the responsibility of safe laser exposure then comes down on to the head of the laser operator/operating company.

On a side note, does anyone here know the people behind the one mile clock? what sort of paperwork did they have to file? did they apply for variances?

[Ugly Dougly]

That's why its getting harder to purchase pointers over 5mW as you said. Thus my "most".

From class IIIa to IIIb (old system) it's kind of arbitrarily divided at 5mW, but as you said, many factors come into play, including atmosphere, wavelength, "overclocking" and - as you said - chemical dilation.

Whatever. We're not going to keep people from smuggling pointers to the playa. We can inform and coerce our fellow burners to use lasers responsibly.

[BetaBox]

i took it upon myself to remove the 700mw blue laser from the Dalek because of said potential for eye injuries. Some people do try to be responsible....

[marck]

Being an owner of one of the first handheld .5 W green lasers on the playa back in something like '08, I found myself getting headaches when I was fooling around with it at home.
I looked into what might happen if the beam was pointed into someone's eyes. Most of it was probably a splash effect, some of it might have been IR radiation.

Here is a WikiLink for anyone who cares. Here is a medical report. And here is a good Tech piece on cheap powerful pointers. Better information can be found in a lot of quality DIY Laser pages and forums.

I would bet you six cases of PBR that most of the visible laser pointers on the Playa are powerful enough to cause damage within half a second of hitting the retina, and this is just the visible light.

My advice is to ignore the laser kiddies who know about how to pump the power up and listen to the experienced hobbyists and professionals who preach caution. Because most of the idiot users think it's hilarious to point it at people, accidents can easily happen. I think of most of those people as douche bags, the others I think of as ignorant fools. The laser should be treated with the same respect as a firearm regardless of it's power.

[Mr.Coffee]

i took it upon myself to remove the 700mw blue laser from the Dalek because of said potential for eye injuries. Some people do try to be responsible....

and for such responsible and considerate actions I applaud you. Same as the people above who were actually taking the time to align their projector in a safer direction.

I'm a laserist by hobby, so obviously this is a bit of a hot button issue for me. I don't want to spam Eplaya with info for other forums, but if you guys want to PM me I'll send you my info for the laser hobby forums I post on. (PL,LPF, etc)

and Ugly Dougly, I agree that "most" might be safer at this point in time, but that almost every one I saw out on the Playa was well over 5, most 300-500, and a few near 1w.

[Mr.Coffee]

Being an owner of one of the first handheld .5 W green lasers on the playa back in something like '08, I found myself getting headaches when I was fooling around with it at home.
I looked into what might happen if the beam was pointed into someone's eyes. Most of it was probably a splash effect, some of it might have been IR radiation.



I would bet you six cases of PBR that most of the visible laser pointers on the Playa are powerful enough to cause damage within half a second of hitting the retina, and this is just the visible light.

A lot of cheaper pointers will negate the IR filter and use the subsequent broadband measurement as the unit's rated power output. since a 532nm greenie is one of the easiest wavelengths to double (1064nm ir), they are some of the more powerful pointers around. but they have a very large IR component without a filter, since the diode driving them is well into the multiwatt range.

[marck]

It was a good laser, expensive and bright, but it ran hot and burned out within two years of occasional use.
I noticed the company scaled back the power on that model to .3 W about a year after I purchased mine.

I may buy, or build, another but only if I can find the time and funds.

[Zhust]

Here I thought this would be a thread about someone who was actually injured.

Do not shine FUD directly into eye.

For your amusement, here is a non-BM actual injury with fingers.

[gyre]

Just make sure the wind is playing on your side, and let the innocent bystanders be damned.

The only lasers I see, are attached to rifles and handguns, so my reaction is to treat a handheld laser pointed at me as a threat.
I bet I'm not alone either.

I can't think of any other rational reason for pointing a laser at someone.

The pepper spray I carry is much less affected by wind than most.


Never got a reply notice to this thread. ??!

[Ugly Dougly]

and Ugly Dougly, I agree that "most" might be safer at this point in time, but that almost every one I saw out on the Playa was well over 5, most 300-500, and a few near 1w.

I agree to err on the side of caution. All of the ones that I build professionally are orders of magnitude more powerful, so maybe I make careless assumptions about handheld devices.

Gyre, lasers can cause permanent eye damage if not blindness.

[Miles]

whoa Jay, NSFL !

[marck]

Never got a reply notice to this thread. ??!

Maybe you did something to hurt it's feelings.

[BBadger]

I suspect that most of the handheld green lasers on the playa were about 30-50mW in power, as they're in that sweet spot where the laser remains portable, and relatively cheap. Some people no doubt opted to impress their friends and fellow burners by bringing along a 445nm laser, which will usually be powered from 600-1.2W in power--quite dangerous. I even saw someone with a 405nm "Blu-ray" purple laser, probably about 200-400mW in power if done right.

The IR component in a green laser is not a huge factor. It is a fraction of the green output (unless the laser is broken), and most of it is poorly collimated, making it less a hazard. In proximities where the IR would be dangerous, the green component is usually sufficient to cause a blink effect, and pupil dilation. I'd worry more about the green than the IR.

[Mr.Coffee]

The IR component can vary quite widely, based especially on internal alingment of the laser. Most of my experience in this realm is with DPSSL lab/show lasers, but I know the pointers are of a very similar construction. A cheap laser that can be knocked out of alignment which also has little or no IR filtering (which is omittied in cheaper models due to heat build up, etc), can output a significantly higher amount of IR than visible light, due to the nature of the design.

Unfortunately, none of the doucebag pointer jockeys will read this thread, or any of the other threads on laser safety, which is the real problem. I'm just keeping my fingers crossed that the next new order fiasco doesn't occur at Burning Man.

[jimbowers@foothill.net]

Jim Bowers (clock artist): Prior to the event, we acquired an FAA variance alerting all aircraft in the vicinity and we obtained a permit/docket number from the FDA which regulates Laser Shows in the State of Nevada. Our laser were also never less than 45' off the ground and angled upward by 1 degree. You may have noticed them sweeping across the nearby mountainside. We also used beam expanders which caused the lasers to "diverge" and expand to a "safe level" as they passed over BRC. When the hour laser was hitting the Crystal we installed in the Temple, it was approximately 18" in diameter in order to avoid reflected beams thru the defraction grating film on the Crystal. - Jim

[junglesmacks]

I suspect that most of the handheld green lasers on the playa were about 30-50mW in power, as they're in that sweet spot where the laser remains portable, and relatively cheap.

I'm betting not. I'll bet you a round of drinks that 98% of all those green lasers are the same, 5mW pen laser with just a fake rating on them. There is a flood of them coming in from China. I fell victim to it twice.. once thinking I was buying a 50mW, and again thinking I was buying a 100mW. They are all the same.. exact.. 5mW pen laser.. just with fake tags on them.

The thing with the green laser is the visibility which gives the illusion of high power.

[BBadger]

The IR component can vary quite widely, based especially on internal alingment of the laser. Most of my experience in this realm is with DPSSL lab/show lasers, but I know the pointers are of a very similar construction. A cheap laser that can be knocked out of alignment which also has little or no IR filtering (which is omittied in cheaper models due to heat build up, etc), can output a significantly higher amount of IR than visible light, due to the nature of the design.

That is true, but when they're knocked out of alignment, the divergence is even worse. Most of the dangerous IR component exits the aperture in the direction of the green beam, with a greater divergence. There is a wide-cone of IR that projects from the aperture, but this quickly loses power.

I'm betting not. I'll bet you a round of drinks that 98% of all those green lasers are the same, 5mW pen laser with just a fake rating on them. There is a flood of them coming in from China. I fell victim to it twice.. once thinking I was buying a 50mW, and again thinking I was buying a 100mW. They are all the same.. exact.. 5mW pen laser.. just with fake tags on them.

Yes, I'd expect that the majority of the greens out there were probably just 5-10mW pointers; however, many of them did compare to the real metered 50mW I brought last year (with about 5mW of IR). A decent-quality 30-50mW green will usually be about its rating, and only cost $20 or so. Up to about 50mW you can run them without them dying too quickly from overheat in the standard Newwish host. People also don't like spending more than about $20-30 on some laser to bring to BM. You can usually tell if the laser isn't just a regular 5mW if you can clearly see the beam from the side from some distance away (like 50ft). A 5mW will have a visible beam, but mostly if you're looking directly down the barrel.

It's fortunate that many of the old mainstay sites for buying cheap green lasers such as eBay have been forced to take down such listings and/or can't export the lasers to the US. I also hope that people are duly impressed by their 5mW lasers, and don't seek out more powerful ones. It was one reason I kept my laser hidden, as I didn't want people trying to one-up me.

It was a bloody shame I didn't get to meet you on the playa. We must've been on entirely different routes the whole time because it should've been damn easy to spot someone glowing in your outfit this year.

[marck]

You can always try to poll the eplayans to see how big the laser they brought was.

[Mr.Coffee]

Jim Bowers (clock artist): Prior to the event, we acquired an FAA variance alerting all aircraft in the vicinity and we obtained a permit/docket number from the FDA which regulates Laser Shows in the State of Nevada. Our laser were also never less than 45' off the ground and angled upward by 1 degree. You may have noticed them sweeping across the nearby mountainside. We also used beam expanders which caused the lasers to "diverge" and expand to a "safe level" as they passed over BRC. When the hour laser was hitting the Crystal we installed in the Temple, it was approximately 18" in diameter in order to avoid reflected beams thru the defraction grating film on the Crystal. - Jim

That's awesome! It's such a relief to know people are doing things properly. Do you guys have any plans to do a clock next year?

[gyre]

We examined a laser sold as green, which was a red laser converted to green.
I think this amplified it's effective output at the same time.

The manufacturers didn't care about regulations.

Impressive results, but far brighter than legal.

[Risky]

I was warned about the blue ones this year, from a friend who makes lasers and has put on several shows this summer in Reno.
He suggested high rated UV protection glasses to protect your eyes from injury.
There are available in shades or clears.

[BBadger]

We examined a laser sold as green, which was a red laser converted to green.
I think this amplified it's effective output at the same time.

The manufacturers didn't care about regulations.

Impressive results, but far brighter than legal.

I don't understand what you mean? You can't convert a red laser to green. Green lasers are made by converting IR into green by "pumping" it through wavelength-doubling crystals. Visible red is not used, however.

I was warned about the blue ones this year, from a friend who makes lasers and has put on several shows this summer in Reno.
He suggested high rated UV protection glasses to protect your eyes from injury.
There are available in shades or clears.

Those are generally not going to help you at BM. UV protection glasses have different meanings, but generally means wavelengths less than 400nm (UVA and UVB protection). People might think this means sunglasses, but these are even worse than no goggles because the darkness will dilate your pupils, and they will not block against blue light, only UVA and UVB, which is around 400nm, not 445nm. Clear, if I get your meaning as non-colored, is not going to help you in the least either. These are blue lasers (445nm), not UV lasers. Maybe they block UVB or something, but if you can see blue, you can see those lasers, and they can blind you. Nor are many goggles designed to protect against the kinds of power densities as these lasers have. A laser beam is a lot different than the UV that might come from, for example, welding arcs (though neither is good).

Even if protective, such goggles would be generally useless for most people. People play with these lasers night, not during the day, and nobody is going to wear welding goggles, or any goggles for that matter, that reduce the visibility of light during the night. There are potentially usable goggles, but certainly not for cheap. I've got actual laser protection goggles for 445nm through UV, and they cost about $100. They're yellow tint, for maximum visible light throughput outside the protection range, but I can't imagine people wanting to wear them at night, nor should they. I also tested other goggles that were similar (but uncertified) to see if there were cheaper alternatives for protecting against 445nm--they didn't hold up, and started melting quickly. Of course you won't have a sustained beam on your face, but still, even in short bursts, it didn't protect.

Cheap, protective goggles are red laser enhancement goggles: goggles with red filters designed to make it easier to see red laser beams, but in doing so help filter out other wavelengths. Nobody would use one at BM, let alone at night. Using them in full daylight takes its toll on your vision, and reduces visibility substantially. I wouldn't even bother with those.

Your best protection is distance, because the beam diverges and also scatters on particles in the air as it passes through them. The 445nm lasers are also multimode and have poor beamspecs, causing them to perform poorly at distances. This doesn't mean you can't still get hurt, but it gives you time to close your eyes or look away, and get out of the vicinity of an idiot who doesn't understand the laser in his or her hands.