From: crystal@glia.biostr.washington.edu (Crystal)
Newsgroups: bionet.neuroscience
Subject: Re: Vision problem and Virtual Reality
Date: 20 Nov 92 18:19:49 GMT
Organization: University of Washington

In <19921119.134808.645@almaden.ibm.com> simonofb@wmavm7.VNET.IBM.COM writes:

>My doctor tells me that I have a vision problem called stribismous
>(sp ?) which inhibits my ability to see certain 3 dimensional
>aspects of scenes.  I don't really understand all of the nuances.
>I have noticed that when I went to Disney World in Florida, there was
>a 3D movie theater where you wore 3D glasses and supposedly were
>able to see a 2D movie in 3d.  All I saw was a VERY blurry image
>that gave me a headache.  I have 2 questions about this condition
>which my doctor was not able to answer.

>1) What exactly can I expect to perceive differently than others?
>- 3D movies obviously that are rendered using the 3D glasses is
>  one I know about.
>- What about virtual reality scenes where the 3D is generated by
>  rapidly flipping between the left and right eye images?
>- What other problems should I expect?

My x-husband suffers from strabismus (crossed-eyes) and his major
complaint was depth-perception.  He could not get into AFROTC due
to his eyes because he would not be able to qualify for a pilot's
license.  Although he had an operation to correct the problem when
he was three, his eyes still do not track perfectly and sometimes
it is hard to tell if he is looking at you or not.   Another result
of the eye problem is physical clumsiness. (Which was fine, since
I just *love* Chevy Chase and his prat-falls...;>)  He also enjoys
reading to the exclusion of nearly everything else, but suffers from 
frequent headaches.  And no, he can not deal with 3-D, nor use binoculars
or microscopes with any success. 

>2) supposedly this problem was caused by my eye doctor's placing
>a patch on my lazy eye for too long a period of time.  Does this
>make sense? What did this do to me physically to cause
>this problem?

While amblyopia (lazy eye) can be a contributing factor to strabismus,
the eye-patch idea has not been proven to be a cause of later
strabismus.  The constant straining of the eye muscles and trying 
to focus with two eyes that just do not track well to begin with is a
more likely cause.  Nearsightedness can also be factor with the same
muscular straining, as well as not wearing your glasses or having poorly
ground lenses. 

Genetics can also play a part in this.  It is a recessive gene in both
humans and Siamese cats (which is where my original fascination with
this comes from).  My X is now married to a woman who also suffers from 
hereditary strabismus.  Her condition was treated non-surgically, but I
forget the details now.

One of their daughters was born with severe strabismus. (a 1:4 chance)
Surgically corrected at age 3, but too late to avoid a learning
disability. :<  (Their newborn son is being watched like a hawk for the
earliest signs of the disorder)  Her post-operative treatment is an eye 
cream that contains cholinesterase (sp?), an inhibitor to acetylcholine
in some post-synaptic neuron that somehow strengthens the eye muscles (or
at least that was what she told me - this could be in error - please 
correct it)

Anyway, a board-certified opthamologist would be your best bet for
accurate diagnosis and information on possible ways to correct the
condition (likely via creams and drops if you are not in "cosmetic"
need for surgery, which if you were, it would have been diagnosed
LONG before now.)  The fact that your doctor didn't give you much info
should tell you to seek a second opinion from  a specialist, rather
than a General Practitioner, which, from your post, I would guess he
was.


>Thanks
>Robert Simonoff
>simonofb@wmavm7.vnet.ibm.com

You're welcome, and good luck! :>

Crystal
  ;>