retina damage from infrared laser :(

Discussion in 'Laser Eye Surgery' started by tomasz.kk, Feb 4, 2008.

  1. tomasz.kk

    tomasz.kk Guest


    three days ago, at my work, i had to install a free space optic
    transceiver for some customer , its an infrared laser, around
    830-860nm at 16mW power, class 1m, its used to connect two computer
    networks between buildings. Both tranceivers have a telescopes
    built in what are used to align both heads to point at each other.
    Anyway, i was looking through that telescope while both tranceivers
    where on, so laser beam was entering my eye through a telescope, and
    an eye contacts , what i was wearing at that time. I was only looking
    through my right eye tho.

    Anwyay, the result is that now i feel a pain at the back of my right
    eye, like a needle picking inside my eye, and my vision is worse
    then the left eye. Also, that dark dot (pupil?) is bigger then in
    the left eye. I thought that maybe it would go away after a little
    while but it hasn't, now its third day, and the pain doesn't stop at
    all:( actually its not constant pain , sometimes smaller sometimes
    more noticible that i can't fall asleep.

    so i looked it up on wikipedia what does it say about class 1m:

    "A Class 1M laser is safe for all conditions of use except when passed
    through magnifying optics such as microscopes and telescopes. "

    and i was looking through a telescope and an eye contact lens:( from
    further reading i learned that such infrared laser can burn retina in
    the eye ball, and cause the sight to be blurry. What do you
    think , is my right eye permanently damaged? can retina
    regenerate? is there any chance that my eye will heal after some
    time? :-(

    tomasz.kk, Feb 4, 2008
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  2. wrote in
    Retina cannot regenerate. I'd suggest seeing an ophthalmologist, and fill
    out any accident reports applicable at your place of employ.
    Scott Seidman, Feb 4, 2008
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  3. tomasz.kk

    tomasz.kk Guest

    Thanks for your responses. Yesterday I went to an emergency doctor ,
    she poured some drops in my eyes and examined them with a flashlight.
    She said that my right eye is injured and i should let it heal, and
    not to look into laser in the future.
    The doctor also prescribed some drops what i should pour into my eye.
    I already tried them but i don't think it would help anything, because
    the damage was done inside my eye. Anyway, today morning, i thought
    the pain was gone, but this afternoon it came back even stronger, so
    definitely something is hurt.

    I don't intend to sue my employer, although actually my superior told
    me that its safe to look through that telescope, but i just don't
    want to mess with him, and i'm leaving that company anyway. Prior to
    installation i also asked a producer whether its safe, and they sent
    me some certificates saying that it
    is totally safe, either class 1 and class 1m their laser products.

    Only after i realized something is wrong with my eye i started
    searching the net and found out that class 1m lasers are not safe when
    look through the optical lenses, and i was wearing eye contacts and
    looked through the telescope. That laser emits 16mW light, while
    after focused it is hundreds of Wats inside the eye. I wrote them
    back and tell what has happened, but they just stopped answering me.

    I just feel bad that i trusted them, and i should have rather checked
    it myself :-( anyway, as i said the pain is still strong, so
    i'm just waiting till its gone, and hope my vision will recover.
    tomasz.kk, Feb 5, 2008
  4. tomasz.kk

    tomasz.kk Guest

    tomasz.kk, Feb 5, 2008
  5. tomasz.kk

    Dan Abel Guest

    I'm not a doctor, but based on my experience with drops, *lots* of
    experience, most of them penetrate the eye and work inside. There are
    various tricks to this, otherwise the drops just drain into your sinuses
    without much chance to work. If you weren't trained on these, call your
    pharmacist or the doctor's office and ask.
    Dan Abel, Feb 5, 2008
  6. tomasz.kk

    p.clarkii Guest

    look, you need to see a retina specialist. a general medical doctor
    or emergency room doctor using a "flashlight" to examine your eye
    sounds ridiculous.

    anyway, if you had actual laser damage to your retina the effect would
    be vision blurring or vision loss rather than pain. eye drops would
    be almost worthless.

    but of course I wholeheartedly agree that you should not look directly
    at a laser again with a telescope!
    p.clarkii, Feb 5, 2008
  7. tomasz.kk

    Mike Ruskai Guest

    It's not looking through lenses that's the problem. That warning was
    probably left vague to err on the side of caution. Looking at a laser
    through contact lenses doesn't change anything over a person who
    doesn't need them to see clearly.

    Looking through a telescope, however, is another question. It's kind
    of counter-intuitive, what a telescope actually does. It makes stars
    brighter, because they are so far away that they can't be resolved as
    anything but point sources. So all the extra light gathered by a
    telescope lens is focused on the same spot.

    But for anything that's not an optical point source, the telescope
    magnifies the size of the image. It's collecting more light, but
    spreading that light over a larger area. The more the image is
    magnified, the dimmer it is (the same amount of light spread is over a
    larger area). As it turns out, any extended image (i.e. not a point
    source) will be brighter to your naked eye than through a telescope.

    A laser very far away might appear to be a point source to a
    telescope, but lasers are also coherent light. Any lens larger than
    the beam width is already collecting all of the light, so it wouldn't
    look any brighter through the telescope than to the naked eye.

    As an extended image, the beam will be enlarged by the telescope. The
    total energy of the beam will be spread over a larger area of your
    retina (whatever isn't absorbed or reflected by the lenses - glass and
    plastic are fairly opaque to infrared).

    That doesn't necessarily make it safe. I'm not familiar with the
    nature of class 1M ratings. You can safely look at the sun with your
    naked eye when it's reasonably close to the horizon, without risk of
    vision loss. That's because the heat can be adequately dissipated by
    your retina. But if you look through a telescope, the sun will be
    dimmer (because it's magnified), but spread over a much larger part of
    your retina. The heat will not be dissipated fast enough, and you'll
    suffer permanent loss of vision.

    Something similar could be true of the laser - it's safe to look at
    with the naked eye, but not magnified (again, something your contacts
    can't do).
    Mike Ruskai, Feb 6, 2008
  8. tomasz.kk

    Neil Brooks Guest

    What were the drops she gave you?? Can you provide the name (or, at
    least, the active ingredient)??
    I don't think anybody here is recommending that you sue anybody. They
    ARE, however, talking about notifying your employer IMMEDIATELY about
    the injury (very smart and very important) AND about pursuing a
    Workers Compensation claim.

    This is NOT the same as a lawsuit. It is designed to provide you with
    medical, and certain other benefits, in the event of a work related

    It sounds like this is ver good advice in your case.

    I hope you're okay.
    Neil Brooks, Feb 6, 2008
  9. tomasz.kk

    KlausK Guest

    You should see a retinal specialist or at least a general ophthalmologist
    KlausK, Feb 6, 2008
  10. tomasz.kk

    tomasz.kk Guest

    it was an emergency hospital, but with different departments, and i
    went to an eye specialist, on a separate floor, so it wasn't just a
    general doctor. i could always go to another eye doctor to get a
    second opinion tho.
    And it wasn't a regular flashlight, definitely some special one, it
    was emitting a vertical beam into my eye, and she was looking through
    some sort of microscope, and examined both of my eyes, asking me to
    look left, right, up and down. Before that she gave me some eye
    drops to make my pupils bigger, i had to wait like half an hour.
    i know, if my retina had been burned completely i would have lost my
    sight, fortunately it hadn't, but something was damaged, the question
    is what and how much?
    normally i wear -2 contacts or glasses to see well, and after this
    laser accident my right eye vision got worse, its like it requires -3
    to see sharp, because that eye doctor allowed me to look through a
    stronger lens and i could see sharper, but i don't know how many
    diopters was that.
    And also my right pupil is still noticeable bigger which is weird, and
    of course that annoying pain doesn't go away. I'm still hoping i'll
    recover from it, i'm pouring those eye drops every couple of hours
    and started taking multivitamin pills, and drinking carrot juice,
    which i read contains vitamin A , good for eyes.

    the eye drops i got are called: diclofenacum natricum 0.1%, 5ml.
    There are some ingredients listed on the box like: Polysorbate 80,
    bor acid, sodium chloride, borax, water, and some other ingredient
    which i can't translate, something with chloride.

    Of course i told about this at my work, but it just made my boss mad
    like he was afraid, so i told him that this only my business, as i
    said i'm leaving that company anyway, for other reasons. I also had
    to deal with microwaves transceivers what used to give me a headaches
    for several days. For now i don't have anything to compensate, and i
    hope i won't , i normally go to work as usual.

    In the morning when i wake up , i almost don't feel any pain, but
    later today it gets stronger, and afternoon its annoying, and its
    strange because its like going down inside my head and to my right arm
    and reaching my hand, like the pain is following some nerve path.

    i don't think there are such specific doctors like 'retinal
    specialist' in my country, only ophthalmologists, which is 'eye
    doctor'. And i understand that its hard to examine an eyeball even
    for a specialist. So thats why i don't know what exactly that laser
    burned , whether only retina cells or some nerves too, what would
    explain why i feel pain.

    Mike, thanks for an interesting writeup.
    a few words about that laser transceiver i was dealing with, here is
    its front:
    and the backplate with a telescope viewfinder i was looking through:

    that laser produces kind of a cone beam, so it was around 50cm
    diameter infrared laser beam pointing at me, the source of the laser
    was ~100 meters away.
    And i think infrared can easily pass through glass, eg my infrared
    keyfob to open the car. And those infrared lasers can be even
    installed indoors behind windows, one of my colleague had such
    installation. I read that only some special colored glass can block
    infrared, so there are some amber protective goggles available. So
    in my case my eye didn't pick a whole laser beam just a part of it
    which was magnified by that telescope, but it was enough to hurt my
    eye, i was installing it for about half an hour although , i wasn't
    look through that telescope all the time, but i can't remember for how

    thanks all for your responses.
    tomasz.kk, Feb 6, 2008
  11. tomasz.kk

    Mike Ruskai Guest

    Seeing as he's posting from Poland, and the documents he referred to
    are from Israel, that's a safe bet.
    Mike Ruskai, Feb 6, 2008
  12. Collimated light from a laser is also effectively a point source, and it
    can be focused to a diffraction-limited spot, just like starlight.
    Now, we don't know how well collimated the source was in this case, but
    if it was designed for long-range transmission with optics at each end
    of the link, it's probably pretty good.
    At close range, the collimating optics of a laser transmitter are likely
    to be larger in diameter than the eye's pupil, so the pupil limits the
    power that reaches the eye. A telescope could be large enough to
    intercept much or all of the emitted beam. For example, if your pupil
    is 3 mm in diameter, and you use a 10X telescope, the effective entrance
    pupil of the scope will be 30 mm (or the objective lens diameter,
    whichever is smaller).

    At a distance, the beam will have spread to be larger than the telescope
    objective, and the intensity will not change much over that diameter.
    A 10X telescope could capture 100X as much light from the beam as the
    naked eye.

    That's why the warning about looking at lasers through binoculars or a
    telescope. It really can drastically increase the captured energy. And
    that energy can be focused to a point - a laser is *not* an area

    The saving factor in this particular case is that the laser was only 16
    mW to start with, there are losses in the optics, and the beam has
    probably spread substantially by the time it reached his position. Even
    with a telescope, only a small fraction of the laser output entered his

    Whether there is permanent damage is something a doctor should
    determine, by actually looking at his retina.

    Dave Martindale, Feb 6, 2008
  13. tomasz.kk

    p.clarkii Guest

    good reply. the additional information is significant.

    then you have seen an ophthalmologist and had a dilated fundus exam.
    sounds like appropriate care. maybe additional testing with a nerve
    fiber layer analyzer would have been more complete. maybe also a
    thorough threshold-level visual field analysis too. perhaps they did
    do these tests already.

    the drops you are taking is called Voltaren in the US and many other
    countries. it is used to reduce inflammation, and it is known that
    deeper penetration of these drops, so as to provide retina-level
    therapeutic effects, actually does work. so using the drops seems
    appropriate too.

    If it takes a stronger lens powers to see more clearly, then that does
    not at all indicate that the health of your eye has been damaged. the
    determinate is whether you can obtain clear 20/20 vision with intact
    peripheral vision. doesn't matter if it takes you a -3.00 lens to do
    it, or a -2.00 lens to do it. it would mean that you have gotten more
    nearsighted, but if you can see clearly in that eye then that would be
    p.clarkii, Feb 7, 2008
  14. tomasz.kk

    Neil Brooks Guest


    I was in Yosemite, killing time while my wife napped ;-)
    Neil Brooks, Feb 7, 2008
  15. tomasz.kk

    tomasz.kk Guest

    Thanks all for your feedback. yes, i am from Poland, and those
    lasers come from Israel, we buy lots of electronics from there.
    It seems like imageshack is having problems, so i'm reposting the
    pictures of that transceiver:

    front lenses, the smaller one emits the laser beam:

    the back panel, with a telescope i was looking through:

    and here is a drawing describing it's laser beam divergence, the
    longer the distance, the wider the beam:

    So that 16mW laser beam was definitely wider when entering the
    telescope and then my eye. But as Dave said, telescope magnified
    part of it, but i don't know to what degree, but according to what
    i've read it could be increased to hundreds of wats focused to some
    small laser spot scribing the retina. At the time i was looking
    through that telescope i didn't feel any pain, but maybe i was just
    distracted as i was standing on a crane platform about 5 floors above
    the ground, and right after i finished i noticed that my right eye
    vision got worse, and later that day the pain started.

    Today i can tell that the pain got weaker, yesterday was the worst,
    so i'm happy, i hope i will recover from it. Although my right pupil
    is still bigger , i found out it may be 'Adie syndrome' but i'll be
    worrying about it later, if it doesn't go away.

    thanks for the info, i started reading about these Voltaren eye
    drops, and found much more useful informations then i found in the
    instruction provided with my drops, eg proper dosing.

    once again thanks for your replies.
    tomasz.kk, Feb 7, 2008
  16. tomasz.kk

    p.clarkii Guest

    i'm sure. its just some medicine to give to a concerned patient along
    with a "medical-sounding" explanation so that they will leave
    peacefully with a smile on their faces. Tobradex is effective for
    that two.
    p.clarkii, Feb 7, 2008
  17. tomasz.kk

    Mike Ruskai Guest

    No. The telescope cannot add power to the beam. It can concentrate
    it or spread it out, but it cannot make the total energy more than 16
    milliwatts (or whatever the laser actually put out).
    Mike Ruskai, Feb 7, 2008
  18. "Mike Ruskai" wrote
    Here important are the wats per unit area. The scribing take place when the
    density (concentration) of energy is enough.
    Szczepan Bialek, Feb 8, 2008
  19. wrote in :
    Workman's comp is not suing your employer.
    Scott Seidman, Feb 8, 2008
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