Biofinity--Spheric or Aspheric? Does asphericity provide a slight presbyopia correction? etc.

Discussion in 'Optometry Archives' started by MS, Jul 5, 2009.

  1. MS

    MS Guest

    Are biofinity lenses spheric or aspheric?


    I don't really understand exactly what the terms mean, but I will explain
    why I ask.

    I recall reading on this NG, probably a few years ago, that aspheric lenses
    provide a little correction for presbyopia in and of themselves, due to the
    asphericity, regardless of multifocal, monovision, etc. That just due to
    being aspheric, they will help presbyopia a little.

    I am both myopic and presbyopic, and wear monovision contacts--the right eye
    for distance, the left for near.

    Before I had Focus Night and Day -4.5 (8.4 BC) in the left eye. (A major
    undercorrection for what I would need for good distance vision in that eye.)
    That used to function fine for near work, but lately my presbyopia has been
    a little worse. The OD changed the left eye to -4.0 for that reason. Since
    that exact lens seems to have been discontinued, he gave me its replacement,
    AirOptix Night and Day (8.6 BC). As I reported in another post, I had
    serious comfort problems with that lens. (It could have been a bum lens
    though.)

    Anyhow, now I have a Biofinity in the left eye, -4.0 power. As to be
    expected, with a half diopter less power in that eye, my distance vision is
    worse, and also the depth perception, ability of the eyes to work together,
    etc. (Therefore, I suggested to him -4.25, which have been ordered.)

    However, one would expect, with the power having been lowered by a half
    diopter on the reading eye, that the close vision, reading, etc., would have
    improved. But surprisingly, it seems to me that my close vision is worse
    now, with the Biofinity -4.0 in my left eye, than it was with the -4.5 N&D
    in that eye!

    I would imagine then, when I try the biofinity -4.25, that the distance and
    binocular vision will be slightly better than with the -4.0, but that the
    reading will be still worse!

    If the Biofinity design is spheric, could the situation described above, of
    worse close vision with Biofinity than N&D, be caused by the difference of
    spheric vs. aspheric?

    If so, what are all the silicon hydrogel lens brands that are aspheric?

    Thank you.

    P.S. Just in case it is relevant, I will give another piece of info. The eye
    doc also made a change in my right eye prescription, the distance eye, for
    which I wear a toric lens. The former prescription was -5.0, cyl -0.75, axis
    180. The new rx for my right eye is -4.75, cyl -1.25, axis 180. He said the
    astigmatism in that eye got worse. That is a pretty major change in the
    cylinder no, from -0.75 to -1.25? Is there any possibility that that change
    in the right eye could have made my near version get worse, even though my
    left eye is the one for near vision?

    Thanks again.
     
    MS, Jul 5, 2009
    #1
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  2. MS

    Jan Guest

    MS schreef:
    They are of the aspheric type.
    It makes a tiny difference, don't expect to much.
    It also differs from one contactlenswearer to another in producing effect.

    major snip.....
    MS, it is difficult if not impossible to give you answers on the
    internet not seeing you and not being capable to examining you.
    You realy should asked your specialist and bring up the issues you have
    complains about.
    Monovision brings you solutions and on the other hand compromises.
    Did you ever tried multifocal lenses or a modified monovisionsystem
    (one monofocal, the other multifocal) ?

    Ask your specialist.

    Jan (normally Dutch spoken)
     
    Jan, Jul 6, 2009
    #2
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  3. MS

    MS Guest

    Thanks for your input, Jan.

    Of course I will ask the OD, next time I see him. Always good to gather
    information on one's own too though, which can give one good questions to
    ask the doctor. Always good to hear different opinions as well.

    I guess if Biofinity is also aspheric, then that could not be the reason,
    for the difference i described.

    Any other input into the situation I described?
     
    MS, Jul 8, 2009
    #3
  4. MS

    Mike Ruskai Guest

    PureVision lenses are aspheric. Felt pretty much the same as N&D to me (i.e.
    not good), but much better optically.
     
    Mike Ruskai, Jul 9, 2009
    #4
  5. MS

    MS Guest

    PS

    The reason that I added, in the PS to my original post, the info about the
    change in astigmatism correction of my right (distance) eye, is that I
    wondered if that could affect the near vision, making it worse?

    Is that unusual, at age 57, to have a change in astigmatism correction from
    0.75 cyl to 1.25 cyl? Well, it is a different OD than last time, and each
    might have a different opinion, on what will work best for a given patient.
    Notice that while increasing the cyl, he lowered the power of that (right,
    distant) eye from -5.0 to -4.75.

    Opinions?
     
    MS, Jul 9, 2009
    #5
  6. MS

    MS Guest

    Thanks for the info, Mike.

    Is there any possibility, that that change in cylinder correction in the
    toric lens in the distance eye, could negatively affect near vision, in a
    person prescribed monovision contacts?
     
    MS, Jul 10, 2009
    #6
  7. MS

    MS Guest

    yes, the right (distance) contact is toric, and that changed from -0.75
    to -1.25 cyl. The left (near) contact is not toric.
     
    MS, Jul 11, 2009
    #7
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