Question About "Add" Value

Discussion in 'Optometry Archives' started by Rich, Jun 25, 2006.

  1. Rich

    Rich Guest


    I am primarily Presbyopic & my prescription I OD & OS +0.5; add 2.00. I
    have progressive lenses & my question is about the reading strength of
    the lenses. Is it 0.5 + 2.00=2.5 diopters or just 2.00 diopters at the
    bottom of the lens.

    Rich, Jun 25, 2006
  2. Rich

    otisbrown Guest

    Is it 0.5 + 2.00=2.5 diopters

    Otis> That is correct.

    (I am not an OD -- but I think they will agree.)
    otisbrown, Jun 25, 2006
  3. Rich

    Rich Guest

    Thank you for the reply. If I were to get bi-focal glasses for computer
    use, the prescription would be something like OD, OS 1.5, add 1.00 &
    that would yield a 2.5 diopter lower lens to read with?


    Rich, Jun 25, 2006
  4. Rich

    Mark A Guest

    That is correct.
    Mark A, Jun 26, 2006
  5. Rich

    otisbrown Guest

    Dear Rich,

    I will make this statement as an Engineer.

    I do not know how old you are, but your refractive state is +0.5
    as you state. The "range" of accommodation (stop-to-stop) reduces
    as we get older. If you "range is 2.5 diopters (let us say), then
    you can see clearly through a +0.5 diopter lens, down to
    about a distance of about -2 diopters. ( -2.0 diopters is
    a distance of about 20 inches -- or normal reading distance.)

    You might take you glasses off and check this. If at 20 inches
    the reading is blurry, then you will need some "plus" to read.

    You can obtain a "simple" plus in the drug store off-the-shelf.

    You might try a +1.25 diopter lens, and see if that meets
    your "near" requirements.

    And further, you might check your distance vision on my

    on Eye-Chart #2 and determine your visual acuity
    with no plus.

    These are easy checks, and do not require OD involvement.

    Just "fun" things to do.

    To further respond:

    Otis> If you Snellen is good, then you need to obtain a "weak" plus,
    so that reading or the "computer" are comfortable for you.

    Otis> Only YOU can check this -- if you wish.


    otisbrown, Jun 26, 2006
  6. Rich

    A Lieberman Guest

    Dear Rich,

    Please disregard Otis's postings. He is not in the medical profession and
    not in any position to give medical advice like above.

    Thank you!

    A Lieberman, Jun 26, 2006
  7. Rich

    otisbrown Guest

    Dear Rich,

    Please disregard Allen's postings.

    He thinks you are intellectually incompetent -- and
    I would bet that you are not.

    To much "paternalism" here. AFTER you have
    done these simple checkes YOURSELF -- you
    can go back to your OD, and talk to him/her about

    Think for yourself.


    otisbrown, Jun 26, 2006
  8. Rich

    Quick Guest

    This begs the question of what you make all your
    other posts as...

    Quick, Jun 26, 2006
  9. Rich

    odisbrown Guest

    Dear Rich,

    Subject: Think for yourself.

    To expand a bit further, when I say "think for yourself,"
    I DO MEAN that you should ignore scientifically
    verifiable human evidence, commonly-accepted
    beliefs, and standards of practice from evidence-based

    I DO MEAN that you should ignore ALL of those "majority
    opinion" trappings and instead pay attention to the widom
    found here:

    You will find many on who disagree with me, but
    perhaps NONE as adamantly as my niece who
    listened to me and became highly myopic nonetheless.


    Avuncular, but Insane
    odisbrown, Jun 26, 2006
  10. Rich

    Rich Guest

    To all that responded to my original question, I thank you. To the
    optometrists on the board, I did just visit one & had my eyes examined.
    My question was just a technical question & replies from both
    professionals & "buffs"(for want of a better term) were helpful. The
    reason I asked was that I had been prescribed progressive lenses with
    the aforementioned prescription after stating that I spend all day on a
    computer at work, not to mention a couple of hours at home. I currently
    had a prescription pair of glasses from another optometrists 4 years
    old(unknown diopter powers & I had forgotten them at work before my
    appointment with the new optometrists). I had told the former
    optometrist(from another state) that I primarily need them for computer
    use. He prescribed a bi-focal with an intermediate power on top for the
    screen & lower for reading. To this day, the prescription is perfect for
    my needs. The single power intermediate is not quite strong enough for
    me to read paper documents, so I need the bi-focal. I can get by with a
    single lower power reading glass(which I did when these frames broke)but
    prefer a stronger bi-focal. The problem is that the new optometrist told
    me progressives were just what I needed for computer use, to read with &
    to correct the slight fuzziness I have at distance. No sooner did I sit
    down in front of a computer when I realized that they were functionally
    useless for me at work. I am a mail service pharmacists who sits at dual
    17" LCD monitors with an image of a prescription on the left screen &
    various data on the right(patient profile, what the tech entered for the
    prescription, etc.). This requires constant checking back & forth with
    some speed for efficiency) to make sure the data-entry matches the
    prescription. With the older bi-focals all I needed to do was move my
    eyes back & forth. The progressives had such a narrow intermediate field
    that it not only took constant head movements to acquire sharpness but
    it also slowed me down to the point of uselessness. I usually ended up
    just tilting my head all the way back to read the screen through the
    near area & not the intermediate. However, after research, I discovered
    that only near vision progressives are appropriate for use on a computer
    & I liked the progressive for walking around, so I went back & changed
    them to transitions(I live in Arizona, very sunny)& decided to order a
    new 2nd pair of inexpensive computer-use bi-focal on-line to replace my
    old one(frames 10 years old, lenses 4 years old, scratched with a slight
    crack from trying to pop them back into a slightly bent frame). Hence,
    my questions about how to order the "add" value. I'm just surprised that
    the computer screen appears clear at 26" through the 2.5 diopter lowest
    part of the progressives. I suppose I should take them to another shop
    to confirm the correctness of the new prescription & obtain the powers
    of my old bi-focals.
    I welcome any insights on my saga & any flames for posting a needlessly
    unsolicited long post.

    Thanks again,

    Rich, Jun 26, 2006
  11. Rich

    Mark A Guest

    Ideally, you should measure the distance from your eyes to your monitor and
    have an OD prescribe an appropriate pair of bi-focals or specially made
    computer progressives for that purpose (that would place computer monitor
    distance vision on the top and then you would add whatever power is
    necessary to get to +2.50 for your reading area on the bottom).

    Progressives are very difficult to fit properly, and a poor lens or frame
    fitting could be causing the problems (or discrepancies) you are noticing
    compared to what you expected. Or the lenses could have been made wrong. I
    would take them to a different optical shop and have them measured (even
    Wal-Mart optical will do this for you).

    There are specially designed progressive lenses available for computer usage
    such as Zeiss Gradal RD, but an experienced optician could design a pair
    using regular progressives (with a high quality progressive lens design) to
    function as computer lenses suing your custom Rx measured by your OD.
    Progressives have some advantages, but your vision will never be as good
    with progressives as it could be with bi-focals at those two exact
    Mark A, Jun 26, 2006
  12. Rich

    Nooblet Guest

    So if some one was -5.00 and had and add of +1 the would really have be
    reading through -4?

    I have always wondered this.. Thanks.
    Nooblet, Jun 27, 2006
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