Eye damage by laser pointer.

[Atomicrox]

Less then 20-30 mW of 488 nm light in my case. Stupid College Senior Coworker flopped the lockuput tag off the safety key and turned on the show control computer, while I was forward of a laser show beam table. He could clearly see I was forward of the safety line. The 25 watt capable SP 171 was idling and cavity detuned to align the table at low power. All the shutter arms popped up as the computer reset the table during boot. Thus I got a painful 100-200 milliSecond exposure. (There is not always pain as a symptom!) That was 1989 or so.

I will obviously sound like an asshole for disagreeing with someone with all your background, but I'm going to throw my 2 cents here anyways.

I find it strange you got visible permanent damage from 30mW. The MPE/safety calculations all allow for a huge safety margin (if I remember well the margin is 10x the power needed to cause damage) and according to them 5mW is safe as long as you don't get exposed for over 250ms. Maybe you got hit by a higher power or got extremely unlucky and it focused very well on a tiny spot...

If lasers that "weak" could cause long term, perceptible damage we would have the media swarmed with actual laser damage cases, because 100mW lasers are very widely available to children and careless users. This is the kind of thing the media loves and they would be all over it if it was common. Even here on this forum it's very rare to see an actual report of permanent laser damage.

I had a laser surgery to avoid retina dettachment and they used a ~200mW 532nm laser focused to a tiny dot. According to my doctor that is about the minimum power to actually cause a decent retina burn. Even then I only had headache for about 2 days and none of the other effects you mentioned (though the tiny spots were made in the peripheral area, which might make the compensation hard to notice). I also asked her to see if I had any (other) laser damage and she said I don't.

Note that this isn't meant to question your story or advertise against laser safety - it's always better to be safe than sorry!

 

[micheal rosen]

I will obviously sound like an asshole for disagreeing with someone with all your background, but I'm going to throw my 2 cents here anyways.

I find it strange you got visible permanent damage from 30mW. The MPE/safety calculations all allow for a huge safety margin (if I remember well the margin is 10x the power needed to cause damage) and according to them 5mW is safe as long as you don't get exposed for over 250ms. Maybe you got hit by a higher power or got extremely unlucky and it focused very well on a tiny spot...

If lasers that "weak" could cause long term, perceptible damage we would have the media swarmed with actual laser damage cases, because 100mW lasers are very widely available to children and careless users. This is the kind of thing the media loves and they would be all over it if it was common. Even here on this forum it's very rare to see an actual report of permanent laser damage.

I had a laser surgery to avoid retina dettachment and they used a ~200mW 532nm laser focused to a tiny dot. According to my doctor that is about the minimum power to actually cause a decent retina burn. Even then I only had headache for about 2 days and none of the other effects you mentioned (though the tiny spots were made in the peripheral area, which might make the compensation hard to notice). I also asked her to see if I had any (other) laser damage and she said I don't.

Note that this isn't meant to question your story or advertise against laser safety - it's always better to be safe than sorry!

I have permanent vision damage in almost the very center of vision in my right eye from getting a 532nm laser 303 shined in it for much less than a second. I think 30mW from an argon ion laser (since they have very low divergence) would definitely be able to cause permanent damage. I, however, experienced none of the crazy symptoms everyone talks about when they have a problem, I simply have a spot near the center of my vision that won't go away, like a permanent after-image, though it seems to slowly be getting better.

 

[DrSid]

I have dark shadow on left eye, on lower left side of the usual vision cone. I started noticing it around the time I was playing with my 1W blues. I had my eyes checked and shows up my retina is perfectly fine. It seems to be some defect in the lens itself. The doctor said he could spot something there but couldn't get a good view at it.
What I'm trying to say is that there are other reasons for vision artifacts. And they add as you get older. It might not be laser related. Good retina scan should reveal it, but from I've seen, some of them are quite low resolution. I think small defects might not be seen even on retina scan, while they still might be noticeable by the person actually using the eye.

Btw. the device for viewing defects in lens and vitreous humor is interesting. It focuses white light into a plane. Using knobs on the device you can move and rotate the plane. You basically scan the inner eye volume with this plane. Then there is common microscope you watch for details isolated by the selective lightning. Problem is you must catch the defect with both light plane and focus plane of the microscope, which seems to be the tricky part.

 

[joeyss]

Few years ago my eye was seriously damaged by laser pointer. From that day on sometimes my eye a bit hurts and my head too. But my eyesight is still ideal.

So, I wonder what will be the long-term consequences of damaged retina by laser pointer? Will I be almost blind on one eye?

Also I wonder, after what time my eyesight will start too be bad... I mean, after how many years after damaged have been done? After 7 years? After 9? Is there any rule in that cases?

Back in august 2010 I bought cheaap green that took 2 AAs and it was one of those stupid lasers that had a a smaller dot so it looked more powerful. It started having connection problems wasn't randomly going on as it was lose. Well I was in my bed. It was glowing very dimly the ir part and what do you know it just went on in my left eye. Couldn't see 50% out of it and I ran down to take 800mg of Advil to stop the headache. Took a week to almost get better and even then it still left a dot on my vision. It cleared up now for the most part but it's still there. pretty sure the advil saved my vision from having worse damage. I was taking it for a few days too. learned never to buy cheap lasers unlesss they're newwish 2 AAAs

What your saying isn't normal and needs to be checked out it shouldn't be getting worse. might be something unrelated that could be very bad.

 

[APEX1]

I would of went as soon as it happened

 

[LSRFAQ]

Let me enlighten you.

The numbers you see for laser safety hazards are based on probability and statistics analysis of animal tests, and a few human volunteer patients in the 1970s... Ie Class IIIA is based on a risk calculated to be a 1 in 100,000 or less chance of injury for a single IIIA exposure.

So while the probability is LOW for damage with low power, it DOES occur on occasion.

For the record, those volunteers generally were already loosing their sight or having an eye removed for other reasons., it was not some sick, uncontrolled, experiment.

The criterion used in the safety studies would have been for a large lesion or visual discoloration of the retinal tissue under a low power microscope. For the most part, rabbits and chimps can't talk. So there is a bit of ambiguity in what defined a damaged lesion.

My burn is tiny...


While most eye surgeons, and my medical service engineer friends will tell you ~200 mW of visible light for a known, active, visible burn through a Surgical Slit Lamp, damage can occur at far less power. Their beam is exiting a fiber before going through lens array designed to produce a fairly big spot at the back of the eye. So you have to factor in power density, not just raw power.

A 171 running at low idle creates a nearly perfect Gaussian beam at 488 nM. When your optical resonator is 1.77 meters long, and your divergence is only 0.56 milliradian, you get a really tight spot at the back of an eye with a very young lens. Blood adsorbs 488 like crazy, so it also depends on the local tissue.

Run the numbers, and the power density is huge...

Also I was working on an actuator, my face was inches from the beam rail, and my vision was fixated on the launching mirror, as I cleaned it. So the geometry was very favorable for a good focused spot.

Back then (1989) a power meter for the low power region was about 2500$, and not needed in the laser show booth of a large amusement park. The internal photodiode based LPMs were all that were used, and are horribly inaccurate. They are there for peaking the cavity mirrors, not for an absolute measurement.

The internal LPM was not calibrated at the low end, the PSU was in current mode not constant light, and that beam could easily have had much more power then the idle setpoint. I know the LPM was off because after the incident I asked the factory service engineer to calibrate the high end off his thermal power meter. The internal LPM was way off.. He visited once a year to install new plasma tubes.

Look at it from an anecdotal perspective... There are "Burners" on here that have fried deep holes in black thermoplastic with 60 mW of green at the Gaussian crossover at the exit of cheap laser pointers..

Magnification of the eye is ~ 100,000 when focused at close up.

Rated beam diameter on a 171 is 1.58 mm, Which works out to be about 1.9 watts per centimeter at 30 mW after correction for Guassian etc.. That is about 1.9 x 10^6 watts per square centimeter at the back of the retina... Give or take a factor of ten.

Burn or Damage, yes... When dealing with Biologic effects, numbers are generally fuzzy..

Steve

 

[Atomicrox]

Gotcha, thanks for the explanation. Guess those crappy beam specs from most handhelds aren't a bad thing after all!

 

[hroldan]

My two cents: yes, go see a specialist for a full check including your eye internal pressure, also not only front but also lateral vision.

Why? it's a long story involving a family member, to avoid boring you, the info told to me comes from a surgeon and ophthalmologist performing laser procedures. You are welcome to disagree just keep in mind I'm not the expect and can't afford telling the whole story. The thing is, he explained that several injuries including permanent procedures with laser can show on your vision (as a lack of detail, vision, shadows, etc), but the eye and brain are actually amazing compensating those problems, so in some cases you can actually have damage but you see the actual clear picture.

So, using a lot of references (because I researched a lot during that time), your vision quality is not the best reference for eye injury, you can actually see things clearly and have a problem, thus specific tests with the right equipment are needed.

Good luck, hope you get better.

 

[hakzaw1]

WHY WRAPAROUND??
it's possible to have your back to the laser source and still take a reflected hit to the eye from reflection on the inside of your glasses as it reflects the laser BACK into your eye.

It's a tooMAH. But seriously though, a forum is not the appropriate place to ask physician related questions. Please seek proper medical advice from a qualified professional.

WRONG this forum is a very good place for this,, ,, IMHO many HAVE been to see a Dr and we need to hear what they now know...
You should be aware that Laerpointersafety.org reads this forum and re-reports whatever is posted concerning any laser related injuries. The FDA reads here as well.

My two cents: yes, go see a specialist for a full check including your eye internal pressure, also not only front but also lateral vision.

YES!!-- worth every penny to know what has happened.

 

[Encap]

Of all hazards, complacency is the most dangerous

For what it is worth here is a good laser safety chart: http://www.lasersafetyfacts.com/resources/Laser-hazard-distance-chart.pdf

There are many others available too: https://www.google.com/search?q=laser+hazard+chart&rlz=1T4FUJN_enUS494US494&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwiupMCMgf_JAhXLOCYKHQ1cCJsQsAQIHA&biw=1350&bih=533

NEVER point a laser, even a laser pointer, at someone's eyes no matter how low the power of the laser.

Light or electromagnetic radiation can result in damage through photothermal, photomechanical, and photochemical mechanisms -- excellent article on the topic of retinal damage--see: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3144654/

 

[Pman]

Can't stand posts like this. Let's ask a serious question that lots will respond too and then the person just dissappears. If I don't see the person respond quickly I assume they are a troll.
That comment has nothing to do with anyones comments trying to help and it's great that we come together and try and protect our hobby.

 

[Alien Laser]

you could try lasik eye surgery, your eye vision can improve by age or degrees i used to ware glasses 0.75 right now i don't my eye vision is 0.25 it improved i can see perfect in distance

 

[danny6]

It dramatically depends on the magnitude of the burn, size of the burn spot, relation to location of optic nerve, and where the location is in the visual field.

Peripheral burns for example, might be almost un-noticable, until the truck hits you. Burns carefully placed to attach a detached retina might result in a general fuzzyness in the vision..


So there is no "typical" laser burn.


In my case, the tiny, tiny, burn received when a co-worker deviated from lock-out tag-out, was noticable for about five years off and on, with some headaches in direct sunlight. Now I cannot find the spot. I did watch the brain remap in real time, so I was lucky as mine was tiny, and barely in the main visual field. It was a moving, fuzzy, black spot on the edge of my main vision at 1 O'clock. However, all I had to do was rapidly pan my head from right to left, then I'd catch it.

It takes the brain quite a while to compensate. The headache lasted for days in my case.
You need to be watching a large white wall to see the remap, which is SCARY to watch. Evidently the brain is constantly using trial and error feedback via saccadic motion to align the eyes. I actually smile when people use the term Safety N**I to refer to me. I was asked to join LPF to encourage safety by some members of the laser show community. Hard to argue with the guy who has experienced the damage, right?


Less then 20-30 mW of 488 nm light in my case. Stupid College Senior Coworker flopped the lockuput tag off the safety key and turned on the show control computer, while I was forward of a laser show beam table. He could clearly see I was forward of the safety line. The 25 watt capable SP 171 was idling and cavity detuned to align the table at low power. All the shutter arms popped up as the computer reset the table during boot. Thus I got a painful 100-200 milliSecond exposure. (There is not always pain as a symptom!) That was 1989 or so.

I'll not regret saying a few weeks of pain, and horrible fear turned me into a laser safety martinet. With GOOD reason. I have a LSO cert for a reason.

My burn is no where near as bad as a friend with over 30 years in the business who looked down the bore wondering why his gas laser had no plasma. The start pulse fired late... He's missing about 1/4th the vision in one eye with NO recovery. That turned him into one of the world's leading eye safety experts. With a degree in Engineering on top of the LSO career.

Recovery or healing is is rare, very rare. What you get if your lucky is brain compensation, and no more. I've watched another person with a severe burn "Dodge and Weave" thru obsticles that are not there, when walking inside in dim light. As I say, no way to estimate what will happen for a given situation.

I've moved to to lab lasers, and knowing what can happen helps where your training newbies around 50 Joule pulses. They tend to pay more attention long term when you tell them your story. The "melted spot" retinal photo collection helps, too.

The quicker you get treatment, the more the surgeon can reduce the bleeding, swelling, and inflamation on the retina. That was not known when I received the injury. Old school logic was live with it, its permanent. New logic, treatment within a hour to a few hours can reduce lesion size or in bad cases, save the eye.

Steroids, Pain Killers, and Nutrients, can contribute to reduced permanent damage.


Problem is, most ER docs may not know what to do, and most optometrists (they make eye glasses!) would have no idea. But the way the medical system works, you often have to see one of them FIRST, especially because of medical insurance procedures. They then book you an appointment well after its too late to reduce the impact... You may have just have severe eyestrain from a near miss, or you may have trauma. More then one person(many airline pilots!) has painfully scratched a cornea or sclera from the dirty hand coming up to protect the un-injured eye. Either way you need to see a pro, and its worth it to strongly pressure for an emergency session with an expert "Opthalmic Surgeon, or Retinal Specialist"



End lesson rant exercise... If you want a second opine, ask Hakzaw, he knows me fairly well...


Steve,

It's hard to answer to all of yours questions since I dont have many time lately... But I would answer to this post, because this post sounds interesting to me. Please tell me more about eye damage that your friend has... And about your damage. How many years after a laser pointer you and your friend have a missing in the vision? I want to know the exact years that took it to appear.

Also as I understand some things about that damage are hard to tell, but generally eyesight isnt affected by that damage, but it often makes a dot that makes to missing some of your vision after some years? Is it hard to live with missing 1/4 of your vision to your friend?

When my eye was injured I had some black dots in the vision that appear quite often at first. But I went to eye doctor and he gave me some eye droops and that eye drops weaken so much that black dots. And then that dots were not black but just grey and year after year I see that grey dots more less often. So as I understand in the future I may see a pernament dot in the vision?