Computer screens and eye strain

Discussion in 'Eye-Care' started by Reason, Dec 29, 2003.

  1. Reason

    Reason Guest

    Hello group,

    For a couple of years I have noticed problems with eye strain and blurring,
    when I use my PC at work. I do not get eyestrain when I read printed text.

    What can improve the situation?
    - Replace CRT screen with LCD?
    - Change screen colours to darker backgrounds?
    - Get special spectacles?
    - Change room lights from flouro to incandescent?

    A 47yo computer programmer, I stare at a computer screen about 9 hours a day
    (work + home), and have done so for 24 years. I expect that I do not blink
    often enough.

    Both my current PCs have 17" CRT with a flat screen. Glare is minimal.

    My eyes are mildly myopic, with mild astigmatism. Until recently it was
    always more comfortable to sit with my eyes about 24" (60cm) from the

    My left eye has glaucoma, which has caused blind areas including a medium
    sized area slightly above the centre of vision. The glaucoma was diagnosed
    13 months ago when the optometrist measured IOP about 45. Damage to the
    retina was already serious. With Lumigan drops, the IOP is now stable at
    about 17.

    I also tend to get migraines towards the end of each working week - for many
    years now.

    Part of the problem might be that newer, graphical programming tools fit a
    lot more information on the screen, using neat but small fonts, with a white
    background. A few years ago I was mostly using 24 by 80 full text on a full,
    14" screen.

    Reason, Dec 29, 2003
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  2. Reason

    Mark A Guest

    Some screens have sharper text than others. Make sure the brightness is not
    too high (this causes the pixels to bloom). Make sure the video adapter
    refresh rate is set to 85 Hz or higher. If the your color is set to 32 bit
    true color, lower it to 16 bit (16K colors). If your monitor and video
    adapter card cannot support 85 Hz, get a new adapter and/or monitor.

    Get an eye exam and tell the OD you need an accurate Rx for computer vision
    at 24" where you spend most of your workday.
    Mark A, Dec 29, 2003
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  3. Reason

    Reason Guest

    Hi Mark,

    The brightness was and is quite low.
    The card is good.
    The monitor is old. Rate is now changed from 60 to its max, 75.
    Please what is the significance of 85 Hz ?

    It was 32. Now 16.
    I will try for a new monitor.
    Would LCD be clearer or less harmful than CRT?
    I will organise that.
    Should I be thinking of transition lenses?
    Is there an optimal viewing distance?

    Reason, Dec 29, 2003
  4. Reason

    Mark A Guest

    The card is good.
    There is no absolute significance to 85 Hz. 75 Hz is probably OK, but 60 is
    terrible and will definitely cause eye strain.
    Not necessarily. Most LCD's are probably better than the CRT you have, but
    may not be as good as a top of the line CRT with high refresh rate and sharp
    text. Trinitron tubes or aperture grill tubes (clones of the Trinitron whose
    patent has now expired) are usually the best for sharp text. But there are
    always exceptions. If you have a choice as which monitor to get, read
    reviews at or
    Transition lenses turn darker in the sun. Maybe you are thinking of
    progressive lenses? There are progressive lenses specifically made for
    computer use like the Zeiss Gradal RD (but you cannot use them for driving).
    Talk to your OD and/or optician about your options based on your Rx.
    Mark A, Dec 29, 2003
  5. Reason

    CarlosWA Guest

    Here are other options that have helped me.

    - Increase your screen size to 19" or 21". Note that a 19" LCD is
    larger than a CRT.
    - Changing screen colors. Try them all. I found that the best one for
    me is High Contrast Black. (Right click on the desktop but not an an
    icon > Properties > Appearance > Color Scheme > select as wanted.
    Also chnaging colors during your work day will rest your eyes.
    - Increasing the icon and font sizes.
    - Localing my office lights so there is no light behind or reflecting
    on the screen. I use two white-light low-heat fluorescent lamps that
    clamp on my desk. I clamped them on each side of me on my desk. The
    arm rotates and is adjustable so I can place them at different highs
    and location. I do not use ceiling lights.
    - Use glasses set for your computer. Measure the distance from your
    eyes to your screen that you like to work at. Take a tape measure to
    the optometrist to ensure that he/she measures your glasses for the
    distance you need.
    - Take rests for your eyes during you work time. At least every two
    hours works for me.
    - Try screen magnification software. I tried Magnifier which comes
    with Windows but I found it lacking (Accesories.> Accessibility >
    - I am currently trying BigShot and it seems that it will do the job
    foor me. It costs aboy $100 and there is a 30-day free trial

    Good luck


    delete "nnoospam" for e-mail reply
    CarlosWA, Dec 29, 2003
  6. Reason

    Dan Roberts Guest


    Here is an article from the MD Support Library that will answer most of your

    Computer Vision Syndrome and Computer Glasses
    by Wendy Strouse Watt, O.D.

    I hope this is helpful.

    Dan Roberts, Director
    Macular Degeneration Support
    Web site:
    Dan Roberts, Dec 29, 2003
  7. Reason

    feeneyl Guest

    I will try for a new monitor.
    I am also a technology professional, spending 7-10 hours
    per day at the computer.

    I switched to a 20" LCD from a CRT about 6 months ago. I made the
    switch because I had not had any trouble with my laptop, but big trouble
    with the CRT on my desktop. The change made a world of difference
    for me. I now find that my eyes feel terribly strained when I have
    to work at a CRT when assisting others. Your mileage may vary...

    My monitor and graphics card - NVidia GEForce2 GTS 32MB, Dell FP20 UltraSharp
    I am using a refersh rate of 60 MHz without any trouble.

    Good luck.
    feeneyl, Dec 29, 2003
  8. Reason

    CarlosWA Guest

    More suggestions

    - Right click on the desktop but not on an icon > Properties >
    Appearance > Effects > changed fonts screen appearance from Standard
    to Clear Type (I have not fully researched this but I think it
    displays better text).
    - Check other keyboards in the stores and see if you need to change
    yours with bigger and bolder characters on the keys. There is even a
    keyboard made for severely visually impaired people which is black
    with bold large white characters.
    - Learn more shortcuts so you decrease the use of your eyes when using
    the mouse pointer.
    - Learn touchtyping so you decrease the work of you eyes moving and
    focussing when switching between looking at the keyboard and the

    Goo luck,


    delete "nnoospam" for e-mail reply
    CarlosWA, Dec 29, 2003
  9. Reason

    Mark A Guest

    I will try for a new monitor.
    LCD's don't work well at high refresh rates (they can't keep up) especially
    if there is any motion on the screen (games, video). But 60 hz refresh rate
    on a CRT is a killer for your eyes and considered totally unacceptable.

    It's always hard to compare a CRT with an LCD, because there are good and
    poor versions of both. Moving from a old CRT to a new LCD may "seem" to work
    wonders, even if a new high quality CRT would have the same benefits.
    Mark A, Dec 29, 2003
  10. Reason

    The Real Bev Guest

    And if at all possible, look at text on the screen of the actual monitor
    you are going to buy -- at the very least, look at the sample. They
    always show pretty pictures in the store, which is absolutely useless
    for judging how clear text will be. Demand that they let you see some
    small print.

    Fry's had some nice no-name 19" CRT monitors about a year ago for $129.
    REALLY nice, and husband and I each got one. Not necessary to spend a
    bundle if you shop carefully.
    I've always hated using anything but single-vision lenses when using the
    computer -- which I've spent at least 8 hours a day doing for the last
    10 years. Having to hold your head in a certain position in order to
    see clearly sucks badly.

    Optimal viewing distance is whatever feels comfy to you. I like to lean
    my elbows in a certain place, which requires me to be 14" from the
    screen. At this distance, I like to read Arial bold type with the
    capital letters 1/10" high, which allows me to cram a lot of stuff on
    the screen.
    The Real Bev, Dec 29, 2003
  11. Reason

    Reason Guest

    Hello Mark, Carlos, Bev, Dan and Feeney,

    All of your responses are useful.
    There are now a stack of options for me to investigate.

    Thankyou all,
    Reason, Dec 30, 2003
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