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>  I have been experiencing problems with double vision and "scattering"
of
> words on the page when reading and/or singing.  At the time of my annual
> eye examination I mentioned this to my doctor.  She explained that my
eyes
> do not come together in the proper manner (I can't give the technical
> explanation) and that eventually she could put prisms in my glasses...

Hi Carole,

Our research group has found that eyesight problems are commonly
experienced by PD patients.  By this, I do not mean such common problems as
short-sightedness that can be overcome by a simple spectacle prescription,
but such problems as you describe, i.e., double vision and "scattering" of
words.

These problems cannot be solved by an optician or optometrist who is
unaware that his client has PD, or is unaware of the difficulties that PD
can impose.

The reason for this is that PD can affect not only the muscles in the arms
and legs, but *any* group of muscles in the autonomic nervous system. A
case in point is the so-called PD "mask", in which the facial muscles are
"frozen" in one position.

Short- and long-sightedness are caused by problems with the curvature of
the lens in the eye.  But double vision is caused by inaccurate positioning
of the whole eyeball when attempting to focus.

This effect can be simulated by very gently applying pressure to the outer
edge of one eyeball.  It is also apparent sometimes when suddenly switching
from close to far subjects, or vice versa.

So when a person goes to an optometrist/optician for measurements to be
taken for making spectacles, just how the eyes respond depends on the PWP's
state of PD at the time.  The ability of the PWP to focus is much lower in
"off" periods than in "on" periods. In cases of dystonia, this ability may
even fluctuate within the one measurement session.

How many PWPs on this list have been told by an optometrist/optician that
they are a "difficult" client?  This usually means that, when using a
system of measurement which audits measurements by referring back to a
previous setting, the operator finds that the client's focus has
mysteriously "shifted" since the last test at that setting.

Our enquiries reveal that very few, if any, optometrists/opticians are
aware of the fact that PD can affect the small muscles around the eye that
position the eyeball, and can, therefore, prescribe a set of lenses that
are ineffective, or effective only from time to time.

The answer to this in the short term is to inform the optometrist/optician
of the fact that the PWP has PD, and the effect that this may have on
measurements, and to arrange appointments only for times when the PWP is in
a stable state. Appointments may have to be cancelled or rescheduled if the
PWP is not stable at the time.

Whether measurement should be made in the "off" state or the "on" state is
not a question I am competent to answer.  But I can theorise that
spectacles made on a prescription based on "on" state measurements will be
ineffective when the PWP is in an "off" state, while those based on "off"
state measurements should still be effective in the "on" state.

This would seem to indicate that an "off" state may have to be "forced" for
the appointments.  This is something that needs very careful consideration
and discussion between PWPs, carers, treating physicians and the
optometrist/optician.

Ultimately, such problems may be overcome by educating *all* health
professionals in the problems associated with treating PWPs.

Jim
* * * * * * * * * * * * * * * * * * * * * * *
 James F. Slattery, J.P., M.A.C.S.
 JandA Computing Consultancy
 E-mail: [log in to unmask]
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