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Thread: Recorded injuries!

  1. #1
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    Default Recorded injuries!

    Has anybody seen any reports of eye injuries caused by lasers?
    Links please......

    Jim

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    i am living proof. less than a second of exposure to a lexel 95 laser caused a permanent dot and blur in my left eye. 3 years later its still not normal. sorry its not an official report but its very true

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    Jim

    I too had been looking into reports of eye injuries from lasers. However, there is one extremely important thing to be considered. There are two distinct areas where eye damage could occur and it is very important that we differentiate between the two, these are...

    1. Eye injuries from lasers in a Lab or workshop enviromnment

    2. Eye injuries from entertainment lasers, or to further clarify this classification - Only those injuries sustained by members of the public whilst attending a commercial lasershow. I would consider any eye injury sustained by a laser operator at one of these shows to fall under classification number 1.

    There is evidence of eye injuries that have been sustained under the first classification and there are people around who have experienced first hand this type of injury, as well as those who have anecdotal evidence such as " A friend of mine had a friend who's second cousin knew someone who blew a hole right through his eye and out the back of his head with a laser"

    Finding evidence of eye injury under the second classification is far more difficult for various reasons. As you are probably aware, I work in Ophthalmic Optics. I have trawled the trade press and done many searches to try and turn up concrete proof of eye injuries from entertainment lasers and I have so far been unsuccessful.

    That is not to say there aren't any, it is quite feasible that there are an odd one or two. You have to consider that anyone who has sustained this sort of injury is probably going to be quite unaware of it. They may have been at a nightclub, had a few drinks (their pupils would be dilated both from the dark and the effects of alcohol) and a laser 'blats' them in the eye with a direct hit. Basically they're too pissed to care and apart from a possible expletive of "F**k, that was bright", would just carry on as normal. The next day, if anything, they may have a slightly sore eye. They may even notice a 'blind spot', but more than likely they will not connect this with the laser.

    It could be some time before they choose to have their eyes checked by an Optometrist, maybe even not until their next eye test is due. By this time it's quite likely that the brain will have somewhat compensated for the injury. The Optometrist, if he sees the injury on the retina, may record this on the patient's record card but there would be no 'Official' reporting required other than this. Even if the Optometrist questions the patient on his injury it would generally be too late to tie it down to a specific incident.

    So, with that example you can see that trying to track down specific evidence is not easy. There probably are a few injuries, but these I suspect tend to go unnoticed. I can assure you that should any injury of this type become apparent and be reported in the trade press, everyone on the forum would know about it.

    In the meantime it's up to all of us to try to provide shows that are as safe as possible. All it will take is one eye injury that can be specifically identified as being caused with an entertainment laser at a public venue and we'll all be saying 'hello' to a whole new raft of legislation.

    For anyone just getting into lasers and thinking of doing shows... I know it's a right royal pain in the as*e doing risk assessments. I know it's extra hassle (and money) incorporating safety features into our projectors, but they're there for a reason - To protect the public and minimise the risk of eye injuries to those attending our shows. So far, the general safety record of the laser entertainment industry is pretty clean (speaking for the UK). Let's try and keep it that way - Don't cut corners and risk spoiling it far all of us

    Cheers

    Jem

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    I agree whole heartedly, it only takes one 'accident' to get the government interested and we will end up with the lasers being controlled as strictly as they are in the US.
    I think you have hit the nail on the head as to why eye injuries tend to go unreported, the only lasers that do crowd scanning over here are in pubs and clubs where everybody is getting as nissed as a pewt, the ones that are done where alcohol isn't involved are always very well organised and all precautions taken.

    Dreamz - Didn't you post a picture last year that simulated your vision?

    I have probably got some eye injury which appear as white spots on the periphery of my vision when I first close my eyes at night. I am a diabetic and have retinopathy every year and nothing has shown on that though. I would expect it would show up something similar to laser eye surgery scarring.


    Jim

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    Here is a quick and simple test for testing the macula yourself. This is NOT a substitute for a proper eye examination. However, it can be used to sow signs of damage to the macula...

    The Amsler Grid is used to test the macula, the very central part of the retina. The test is simply a grid made of evenly spaced horizontal and vertical lines. A small dot is located in the center of the grid for fixation. Simply follow the instructions below the grid.

    While focusing on the dot in the center of the grid, with one eye covered, ask yourself the following questions:

    Am I able to see the corners and sides of the square?
    Do I see any wavy lines?
    Are there any holes or missing areas?
    If the lines of grid do not look straight or areas appear to be missing and or distorted, you should arrange to see an Optometrist/Optician/Eye Doctor

    Cheers

    Jem
    Attached Thumbnails Attached Thumbnails amsler.gif  


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    Quote Originally Posted by Jem View Post
    While focusing on the dot in the center of the grid,
    What grid

    Jim

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    Oh dear...

    Have you been misreading the safety labels on the lasers again - 1Kw instead of 1Mw - Perhaps it's time for an eye test, we can fit you in next Tuesday

    Jem

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    Quote Originally Posted by Jem View Post
    Oh dear...

    Have you been misreading the safety labels on the lasers again - 1Kw instead of 1Mw - Perhaps it's time for an eye test, we can fit you in next Tuesday

    Jem
    I only look at the laser to make sure its bright enough.... honest.

    Jim

  9. #9
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    mixedgas is offline Creaky Old Award Winning Bastard Technologist
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    get the book by David H. Sliney of the US army. Read the case descriptions in the back, and prepare to puke when you read the one about the 50 watt q switched IR. if I remember correctly, the quote goes like "the researcher screamed as he watched floating tissue move around, then his vision went red as he watched blood fill his eye...."

    ah heck forget the books, just google sliney and laser.

    Oh and the amsler grid only does the main vision, it doesnt test the peripheral, and you'll find out about thet when the truck hits you as you cross the sidewalk ;-) The test for the peripheral is a video game like sphere you look into, with a atari type joystick and lots of faint yellow leds and projected dots your goal is to press the button as soon as you see the dots, while staring at a fixation dot, the nursie type watches a monitor to make sure your not "peeking" around and looking straight ahead, and hits a button cuing a random sequence of leds and projections, and the computer maps out your vision. I set the office record for fastest time to perfect score for my age range when I had "unspecified optical neuropathy" a disease that hits 20-30 year old males for unknown reasons and plays tricks with your vision.

    In a emergency, or for self test, you could do it with control software, galvos, a big room with white walls, and a garden ball to project a faint beam over a wider angle. Set up a pointer for the fixation dot, and have a friend hit the beamshow keys.

    Note :"Garden ball, mirrored hollow glass reflecting sphere popular in US flower gardens, comes in may colors and styles, one of which is refletive silver, cost from ~20$ for a small one to megabucks"

    Steve Roberts

    PS I too have a very very tiny burn, I was working in the remote house of a very big laser show when I was 19, a idiot walked up to the main console, tore off my lockout tag and booted the control cpu by turning the KEY!. All the beamtable arms momentarily lifted as the CPU initialized, the logic was in a undefined state, and I took a few hunderd mW into one eye. It was minor and its not fun to watch your eye and brain remap the retina in real time. I have no evidence it was ever there. Big time blindnss comes if you hit the fovea in the macula, thats where the nerve joins in to pull out the data. Plus your eye is always shaking back and forth to enhance resolution, so its hard to find if you have a minor one. Oh and as you read this and start to scan your eyes around the room, casuing stress, dont panic if you find yor permanent blind spot, its where the nerve hooks into the retina and we all have one. You can find directions for viewing it on the net.

    This is why master safety shutters should ALWAYS!!!!! be a manual switch. I followed procedure by having the tag on the console, he didnt even bother to read it. Lousy UNRELIABLE Humans!
    Last edited by mixedgas; 11-08-2007 at 09:07.

  10. #10
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    Quote Originally Posted by mixedgas View Post
    Oh and the amsler grid only does the main vision
    Precisely, that's why it says 'macula' the very centre of the retina and therefore the visual field. It's a simple test that anyone can do. We have field screeners at work which use frequency doubling technology to test peripheral vision, these, alongside traditional bowl type screeners cover the whole visual field.

    I just wanted to put something up there that was a quick and simple test for the central fields, besides, this is where any damage would potentially be most noticable on a day to day basis.

    So, my example of... " A friend of mine had a friend who's second cousin knew someone who blew a hole right through his eye and out the back of his head with a laser" wasn't far off the mark when considering your guy with the IR laser

    Cheers

    Jem

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