Thanks Mike, David, Scott...

Just to make sure, I say torsional, because reading about the diplopa
problems caused by a fourth nerve palsy, I don't believe that I tuck my
chin in and bow my head forward. I actually tilt my head to the right
(or was it the left) as was observed by the opthalmologists.

I also remember seeing the images in one of the maddox tests, in which I
saw two lines but not parallel to each other.

There is a certain amount of vertical displacement though when I cover
each eye in turn which I don't know whether prisms would at least help
with that bit?

Im glad therefore everyone has said prisms won't help. The doctor said
this too.... I took him at his word.... But I was concerned about
whether having to fuse images were causing any great physical or mental
strain and therefore whether the appropriate glasses would have any benefit.

So the end result is, if this is torsional diplopa, prisms won't help, I
just have to put up with the effects of decompensating and sort out
exactly why I decompensate.

Thanks
Simon

I tend to agree. Torsions are tough to fix. One time I resorted to frosting
one lens with scotch tape just so he could function.

-MT

Simon Dean <sjdean@simtext.plus.com> wrote in news:51sgsfF1lvu49U1
@mid.individual.net:

If the diplopia is truly torsional, I don't think that a prism would help.  
Possibly, you might be able to use prisms to bring the eye to a
horizontal/vertical position where secondary and tertiary muscles would
resolve the torsional disparity, but it wouldn't be the same as using prism
to resolve a horizontal disparity.  I think there would be a low
probability of success, and would require alot of trial and error, in any
case.

The good news is that torsional fusion is more forgiving than vertical and
horizontal, so you don't need to get as close.

Ok,

So,

Let's say, I have a 4th Nerve Palsy which is causing a torsional
diplopia. My fusional amplitudes are pretty good and I converge the
images correctly most of the time, unless I go for those dissociation
tests such as W4D and Maddox, but every now and again in the real world,
I begin to decompensate.

Now, would any prism glasses help with the decompensation, or would
prism glasses help all the time to relieve any mental/physical strain
with having to compensate all the time (if indeed that's what Im doing)?

Am I getting a hang of these things now? Think I finally understand it.

Ta
Simon