Bad vision at the end of the day, and w/ light changes:

Discussion in 'Eye-Care' started by Matt C., Oct 29, 2003.

  1. Matt C.

    Matt C. Guest

    I'm having problems with my vision at the end of the day.

    I'm a computer programmer, and spend a fair amount of time in front of the
    computer when I'm not at work. I suspect that has something to do with my
    problem. My vision is fairly clear most of the day, but from twilight on I
    get distinctly more nearsighted, even indoors. Sometimes I will experience
    blurry vision early in the day if I change my environment, for example I had
    very blurred vision after walking into the library the other day.

    If I squint, it helps bring things into focus, sometimes dramatically.

    I've been to two eye doctors. One basically said "I don't know what's
    wrong, try stronger glasses". The other suggested it was the near work I do
    all day, causing my eyes to lock into near focus. He suggested some eye
    exercises (which I have been doing) and also gave me a new prescription. I
    had what seemed like an extensive run of tests with each doctor, and neither
    of them found anything they considered alarming, but I'm still not soothed.

    I am 33 years old. From what I have read, an increase in nearsightedness is
    unusual for people my age. This worries me. Also, the fact that my vision
    problems are much worse at night, and plausibly related to changes in the
    light level, seems significant to me, but not to either of the eye doctors.

    My main concern is that something is going on that will make my vision
    continue to get worse, that would have been avoidable if I had known what to

    Has anyone here had similar experiences, or have any insight to offer beyond
    what I've already been told?

    Matt C., Oct 29, 2003
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  2. Matt C.

    Otis Brown Guest

    (Matt C.) wrote in message

    Dear Matt,

    I hope you are not wearing minus lens glasses now.

    The first thing a person sees on the threshold of
    nearsighedness is some loss of distant vision in

    This is a good indication that you should review
    the major opinions about the eye's behavior, and
    reach a point where you make a decision about
    your course of action.

    The opinions are strong -- and directly opposed.

    Others are going to post statements to the effect
    that working all day at 15 inches (-2.5 diopters)

    The alternative I suggest is to use a plus lens
    for working on the CRT, and of couse check
    your vision by reading an eye chart. If you
    are interested, then read my site.

    I give this advice to pilots who have the
    maturity to understand the nature of this advice.
    So read the "legal" part of my site to understand
    that the responsibility is yours.

    So enjoy the "read", and think about it.
    Take no action until you judge that you
    are comfortable with you choice.



    Otis Brown, Oct 29, 2003
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  3. (Matt C.) wrote in
    Do you have any risk factors for diabetes?

    Scott Seidman, Oct 29, 2003
  4. Matt C.

    Dr. Leukoma Guest

    A couple of observations: If squinting helps, then the problem must be
    optical in nature. You could have a form of myopia that is transient and
    related to your long hours at the computer. This is not uncommon, and is
    caused by your accommodative muscle not being able to relax.

    What would cause your vision to change with light level? For one thing,
    the pupil changes size. Besides regulating the amount of light, the pupil
    also helps to eliminate spherical aberration. Do you see better or worse
    in a low light environment?

    Something that can cause blurred vision, but should not be responsive to
    squinting, is dry eyes caused by staring at the monitor. A person with
    marginally dry eye will also experience changes with the environment, air
    currents, humidity, etc., but not with illumination levels.


    (Matt C.) wrote in
    Dr. Leukoma, Oct 30, 2003
  5. Matt C.

    Matt C. Guest

    (Otis Brown) wrote in
    I am not. I had already decided not to wear my new prescription at the
    computer. My vision had only gotten worse with my previous prescription.
    At present I do not wear any glasses while doing computer work. I will
    probably try the positive lens suggestion from your website.
    In some ways this is comforting, to think that my case is somewhat normal.
    However, the light sensitivity is pretty pronounced in my case, and I'm
    still somewhat worried that more is going on here.
    From what I have read so far, your arguments seem plausible, and your
    recommendation for treatment does not sound very risky. I will probably
    give it a try. If I do, I'll report back here in a few weeks.

    Thank you for the response and for the information on your website.

    Matt C., Oct 31, 2003
  6. Matt C.

    Matt C. Guest

    Not that I am aware of, nor any other indicators of diabetes. However, I'm
    planning to go get a pee test just to cross this off the list for certain.

    Thanks for the reply.

    Matt C., Oct 31, 2003
  7. Matt C.

    Matt C. Guest

    Ok. I have noticed that my vision degrades even on days where I have not
    been working at the computer. I've not measured this closely, though.
    Noticeably worse with less light. Again, I have not measured closely, but
    it seems like my vision gets slightly worse as the day goes on, and then
    significantly worse once the sun starts to go down.

    It seems like fluorescent lighting also causes my vision to get blurry.

    My computer monitor was pretty bright--too bright--for quite a while. Is it
    possible that this has something to do with my light sensitivity, perhaps my
    eyes got used to an unusually small pupil size?

    Thanks for responding.

    Matt C., Oct 31, 2003
  8. Matt C.

    Dr. Leukoma Guest

    (Matt C.) wrote in
    Could you give us your spectacle prescription, please?

    Dr. Leukoma, Oct 31, 2003
  9. Matt C.

    Matt C. Guest

    Sure. It says, R: -50 sph, L: -175 sph. I assume this means -.5 and -1.75
    in the diopters that I've been reading about.

    I am not sure this was the most reliable eye exam. I was wearing my old
    glasses (considerably weaker than this prescription) and actually tested
    better when I took them off than when I was wearing them. For what that's

    Matt C., Oct 31, 2003
  10. Matt C.

    Dr. Leukoma Guest

    (Matt C.) wrote in

    OH, now that's interesting. Without your correction, you are functioning
    monocularly, i.e. right eye for distance and left eye for near. Even with
    spectacles, that is a fair amount of anisometropia (prescription
    difference) between the two eyes, and you may not have good binocular
    vision under those circumstances, either. It is possible that your blurred
    vision is a result of poor binocularity, unstable fusion, or excessive
    accommodation secondary to fusion problems.

    By the way, when do you wear your eyeglasses? Are your symptoms occurring
    only when you wear your spectacles?

    Try covering one eye and see what happens (with spectacles on, of course).
    As you can see, there are several possible scenarios, all involving stress
    on the visual system.

    Also, I do NOT advise that you wear low plus reading spectacles. Save the
    $15 for a thorough binocular vision work-up and possible contact lens

    Dr. Leukoma, Oct 31, 2003
  11. Matt C.

    Matt C. Guest

    I have tried covering first one eye and then the other. It does not seem to
    change anything (other than the obvious decline in vision when I have my
    right eye closed). If there is something more sophisticated I can try, I
    would certainly be willing to do so.
    I'm not wearing them at all; the prescription hasn't even been filled. My
    vision is usually quite clear during the day. (Like I said before, I
    question this most recent prescription.) My symptoms typically show up at
    twilight and at night. I do sometimes have blurry vision during the day
    when I change location. I'm forming the hypothesis that these daytime
    problems are related to changes in the light level or possibly fluorescent

    It seemed to me, and still seems to me, that the eye exercises he
    recommended (looking at distant objects periodically), and the prescription
    he gave me, are in direct contradiction to each other. I decided to just do
    the eye exercises and skip the glasses.

    (Also, my vision got worse when I was wearing my old prescription regularly.
    That played into my decision to not get the new glasses.)

    I am now contemplating getting this stronger prescription filled, just to
    make sure that the problems I'm having with night vision are in fact
    correctible with glasses. Kind of an expensive experiment, but I'd would
    like to confirm that my night vision problems are lens-correctible.
    As above, it doesn't seem to make a difference. I could try wearing an
    eyepatch during the day, if a brief test is not sufficient.
    Do you mind discussing why? The argument for wearing plus lenses for close
    work makes sense to me.

    Matt C., Nov 1, 2003
  12. Matt C.

    Otis Brown Guest

    (Matt C.) wrote in message

    Leukoma> > Also, I do NOT advise that you wear low plus reading
    spectacles. Save the $15 for a thorough binocular vision work-up and
    possible contact
    lens fitting.

    Matt> Do you mind discussing why? The argument for wearing plus
    lenses for close work makes sense to me.

    I would like to hear the reasons also.


    Otis Brown, Nov 3, 2003
  13. Matt C.

    Dr. Leukoma Guest

    The fact is that Matt C. reads with his left eye, which already has a power
    of +1.75. He might be using his right eye to view the computer screen,
    depending on the working distance. But, Matt is essentially monocular,
    with a natural form of monovision. I know that it is far easier for Matt
    to understand the simplistic notion of wearing plus lenses for close work
    than it is for him to understand the concepts of binocular vision.

    Otis, on the other hand, knows better...or does he?


    (Otis Brown) wrote in
    Dr. Leukoma, Nov 3, 2003
  14. Matt C.

    Dr. Leukoma Guest

    (Matt C.) wrote in
    As I said in another thread, your left eye (-1.75) has a focal distance of
    about 25 inches. Therefore, within that range your left eye does all the
    work. This is called monovision. At night, under conditions of poor
    illumination where peripheral visual cues are lacking, diplopia tends to
    occur, or a situation in which the blurry image from the left eye is
    superimposed on the clearer image from the right eye typically ensues.
    Prebyopes who wear one contact lens for close work often complain of night
    vision problems, especially as the presbyopia and the power of the reading
    lens increases.

    Lack of fusion and accommodation can lead to other issues, such as
    convergence problems. Also, there will be an intermediate range of vision
    where both eyes will try to dominate. Typically, this condition tends to
    become more embedded as the "near-dominant" eye becomes more nearsighted
    until the symptoms of a binocular vision disorder become more pronounced.
    Speaking as one who has seen and treated countless cases like yours,
    treating yourself with over-the-counter reading glasses makes absolutely no
    sense to me. I dare say that I would be surprised if it made sense to any
    eye care professional.

    Having said that, I recommend that you put the $15 toward a thorough
    examination from a good optometrist who will take the additional time to
    analyze your work situation and try different lens combinations, as well as
    giving you a thorough explanation.

    Dr. Leukoma, Nov 3, 2003
  15. Matt C.

    Otis Brown Guest

    (Matt C.) wrote in message

    Re> Has anyone here had similar experiences, or have any insight to
    offer beyond what I've already been told? Matt

    Dear Matt,

    Subject: The second (engineering) opinion

    You have recognized that a plus lens might be
    a good idea for consistent close work.

    Indeed this is the recommendation of optometrists
    who are familiar with your type of work.

    It is true that the plus lens is a lower cost
    item -- but that is not the point.

    The point is that maybe you had a "bad day" when
    your eyes were measured at -1.75. Perhaps
    the OD has a "bad day". Maybe your eyes
    are more like the old prescription.

    You might double check this yourself.

    In any event here is the experience of
    a pilot who wat measured to be -1.0 diopters.

    Maybe his experience with be a factor in your

    Just remember, an ounce of prevention is
    worth a pound of cure.




    1. Name and Date: Matt, Pilot 3/16/03

    Subject: Otis, can you help me from -1.0 D?

    Hi my name is Matt B. I am 21 years old and have a
    prescription of:

    Left : -0.75 and
    Right : -1.00.

    I am very interested in improving my vision to 20/20.

    This prescription is not good enough for the Royal Air Force,
    at present I would fail the eyesight test.

    My dream is to become an RAF pilot, so any efforts that I can
    make to improve my vision without surgery would be ideal.

    2. From: Otis

    Subject: Recovery from -1.0D, or 20/70

    Dear M. B., I appreciate your interest. Generally, -1.0
    Diopters is considered to be equivalent to about 20/70.

    No one can guarantee success, but a number of pilots have
    cleared their distant vision by the plus-lens preventive method.

    I will provide all the assistance I can. However, you must
    make all the confirming measurements. Best, Otis

    3. Name: Matt B.

    Subject: How should I use the plus

    I have read all the items on your site and to be truthful am
    somewhat confused.

    Does this mean that I can prevent my eyes from getting any
    worse or can I improve them.

    Should I wear them all day or just for close up work as I am
    doing now?

    4. Name: Otis

    Subject: Initial Info: How to use the plus

    Dear MB, The plus lens is sold in the USA everywhere with no
    prescription required. Values run from +1.0 to +3.75 D

    Select a lens of about +2.0 diopters. Pick up some reading
    material an push print, i.e., find the point of blur for
    comfortable reading.

    Practice reading, for 10 minutes, and then look over the tops
    of the lens at the eye-chart. Some times you will see rapid
    clearing by this method. Best, Otis

    5. Your Name: Matt

    Subject: More Measurements

    I found that I could easily read the letters. I downloaded a
    Snellen chart which I printed out and stuck on my wall.

    At twenty feet I found that I could read the 20/20 line
    although it was not crystal clear when using both eyes.

    With just my left I could see 20/30 although I could make out
    most of the 20/20 line and with just my right eye I could see
    20/40 easily but most of the 20/30 line.

    6. Your Name: Otis

    Subject: Vision Status

    To: MB, Pilot. I am pleased you checked your vision an
    found it to be approximately 20/40 under room illumination. You
    now have a base-line to compare your improvement.

    You need to improve by about +1/2 diopter. Please read pilot
    Christer's comments on his efforts. They should help you
    understand what it will take to clear your distant vision.

    I hope you understand that this is a slow process. If you
    keep working, you can achieve what Dr. Colgate achieved. Best,

    7. Your Name: Pilot M.B.

    Subject: JAA Test, Part 1

    Otis, Today has been a good day!! I passed my medical
    without a hitch - you should see the huge grin in my face. I know
    it is only a JAA class 2, ... but I was quite worried that I
    would fail the vision part. The examiner made me cover one eye
    and look through a mirror at the chart on the wall behind me.

    The chart was the one with the rotating Cs which I found
    pretty easy. After that I had the standard Snellen chart, at
    normal room illumination, which I also passed.

    8. Your Name M.B.

    Subject: Pass JAA -- Part 2

    I'm not sure quite how I did it but I scored a 6/6! Looks
    like all the work that I have been doing is paying dividends.

    I want to personally thank you Otis for introducing me to
    this method of clearing up my distance vision. I am now more
    motivated than ever to keep up with my efforts.

    Think I might have a beer or two this evening, such a weight
    has been taken off my shoulders. I raise my glass to you my

    9. Your Name and Date: Otis 3/29/03

    Subject: JAA Test, Part 3

    Matt, Both of us are VERY PLEASED at your success. 6/6 means
    you read at a distance of 6 meters what the normal pilot can read
    at 6 meters.

    The size of the characters is 0.88 cm. They should write:
    6/6/0.88cm to be perfectly clear to the pilot who wishes do his
    own checking.

    As you know, pushing print, doing your own eye-chart
    checking, and using the plus lens properly is the key to success.
    Congratulations! You must continue this work (even though
    you are at 20/20) to make certain your vision stays at
    20/20. Best, Otis
    Otis Brown, Nov 7, 2003
  16. Matt C.

    Matt C. Guest

    I appreciate the explanation. Two things make me wonder if my night vision
    problems are substantially due to diplopia.

    1) Closing my left eye at night does not improve my vision in my right eye
    (which I agree is doing all the distance work). Is there any lingering
    effect with diplopia? If so, could I test for diplopia by keeping my left
    eye closed for (say) 20 minutes?

    2) If, at night, I make a slit with my fingers and peek through it, my
    vision is dimmer but much sharper (it takes some meddling to get it right,
    but it works). This agrees with what my most recent eye doctor said about
    my problems with my night vision (larger pupil size). It does not sound
    consistent with my problem basically being an inability to integrate images.
    I agree that OTC reading glasses are not going to help with any problems
    that are basically caused by monovision. However, I am still concerned that
    the near work I do all day is degrading my distance vision generally.

    What would you think of the idea of me getting a pair of prescription
    "reading" glasses such that both of my eyes were near their outer focal
    limit while I was at work? Say (just a guess), R: +0.5, L: -0.25?

    If you think this is not a good idea, do you think it is likely to cause
    actual harm, or just that it is pointless?
    I am hoping to find an eye doctor that I can see eye to eye with, so to

    Matt C., Nov 9, 2003
  17. Matt C.

    Matt C. Guest

    (Otis Brown) wrote in
    What do you think of Dr. Leukoma's observation that my vision is basically
    monocular? I find the argument for the plus lens for close work plausible,
    but it is true that if I get reading glasses that work for one eye, they
    will be completely out of range for the other. Do you consider this
    significant, and if so do you have any advice about handling it?
    Been doing this with a home-printed Snellen chart. I am finding a lot of
    variation, depending on time of day, illumination level, and type of
    I appreciate your interest and your suggestions.

    Matt C., Nov 9, 2003
  18. Matt C.

    Otis Brown Guest

    I do not agree with Dr. Leukoma.

    But check it out. Can you see three D objects? Has anyone
    of the oDs you consulted stated you have mono-vision?
    There is a slight difference between the two eyes.
    Differences of up to 0.75 diopters are with in a
    normal or gaussian spread. This was suggested
    by Dr. David Robins in a previous post -- and I agree with it.

    Matt> I find the argument for the plus lens for close work plausible,

    Good, but from past experience, I can tell you it is not
    easy and takes a great deal of personal resolve.
    If you are casual about it -- just do not bother.
    The pilots who have used the method go ALL OUT.
    You can check my site:

    for information to that effect. If you decide to
    take any action at all -- think about it. It is like
    advocating that a person go on a diet and lose 20 pounds.

    While conceptually correct -- most people are simply
    not going to do it.

    The minus lens is indeed 100 times easier. Most doctors
    do not recommend that a person use the plus -- simply
    for the reason that the person concerned just will not
    do it.
    That depends on the physics of the situation. Since you
    have been examined by an OD, you can feel confortable
    that he has ellimanated all ORGANIC problems with your eye -- and
    has determined that a -1.75 dipoter lens will sharpen
    your vision to the maximum extent possible. It is
    possible that it is "over-prescribed", and I would check
    this by reading 3/4 inch characters at 20 feet in room
    illumination. Most people will not even do this simple
    check. Please do not do any of this on my account.
    You asked for general information about "potential alternatives"
    and it is always pleasant to think about them.

    Since we will never know what actions you might take, the
    issue is a matter of your own judgment.

    Matt> Do you consider this
    significant, and if so do you have any advice about handling it?

    If your vision were 20/40 and 20/50 (by your own checking) I would
    not consider the issue as important. Typically you will see
    this difference between the eyes that have 20/20 and focal
    states of +1/4 and +3/4 diopters. In this case both
    eyes would be 20/20, and the person would not be
    aware that there was a difference of 1/2 diopter.

    You should ask youself how important your distant vision
    is to you -- really? Unless it is VERY IMPORTANT, such
    as you do not "make" the RAF, I doubt that you would
    have the motivation it really takes to clear you distant vison.
    [This is NOT a criticism, it is just the way most of us

    You will get a lot of hostility against this concept that
    evolution designed a very sophisticated eye that "follows"
    the visual enviroment, but that is the way that I see it.

    These arguments have nothing to do with money. Rather
    they have goal of learning and understanding new concepts -- and
    methods that can develop from them.



    Otis Brown, Nov 10, 2003
  19. Matt C.

    Otis Brown Guest


    Here is some commentary by Dr. Robert Levy who reflects
    the "second opinion", about keeping the minus lens
    off your face, except for driving a car when it is
    absolulty necessary.


    The Health Profession's Response to "Problems With Poor Vision".
    [The previous "myth" was that there is no relationship between
    the focal state of the eye and its visual enviroment.]

    Dr. Robert Levy:

    I must strongly disagree with at least one "myth" about poor vision
    Dr. Jay Siwek mentions [Consultation, 9/11/91]. He says doing close
    work does not harm your eyes and then goes on to talk about three
    sight- threatening diseases. While it is true that close work does not
    cause the kinds of blindness that glaucoma, cataracts and macular
    degeneration do, such fine focusing for extended periods can cause
    nearsightedness, a far more common occurrence.

    Day after day, year after year, I see patients who get more and more
    nearsighted from doing close work, particularly if they have been
    wearing a distance prescription while doing their close work. The
    vicious cycle is that you read and do your homework, become
    nearsighted, get distance [negative lens] glasses and when you go back
    to read and do your homework you become more nearsighted.

    People who take their glasses off to read (if they can) or who wear
    bifocals [plus lenses] to reduce the prescription for near focusing
    show a much slower progression into nearsightedness than those who
    read with distance glasses on. One study of an Eskimo village being
    taught to read showed that after two generations of reading, virtually
    none of the grandparents' generation needed distance glasses, about
    half of the parents' generation did and virtually all of the
    children's generation did. This is the best example of reading and
    close work causing nearsightedness.

    Otis Brown, Nov 10, 2003
  20. Matt C.

    Matt C. Guest

    (Otis Brown) wrote in

    As I understand it, the way to use positive lenses for vision rehabilitation
    is just to read print at your outer focal limit. I don't understand why you
    say this takes a great deal of personal resolve. I've tried reading this
    way; it's mildly inconvenient, but I'm pretty sure I could get used to it.
    Is there something I'm missing?

    Matt C., Nov 11, 2003
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