I wasn't suggesting any kind of cheating on the tests - I have always
been able to see such images, even the totally random-dot ones,
without resorting to any tricks. My point was that even though my
stereopsis capability with such images was normal, I did not maintain
binocular fusion when looking at the "real world".

What I'm recovering now is far from your "accurate" level of detail,
but the feeling of 3D space, even though it lacks detail, is dramatic.

I totally agree about stereopsis. I must have had relatively normal
vision in early childhood. And I was certainly deprived of normal
binocularity starting around age eight. But I somehow maintained the
ability to view stereo photographs and stereograms.  

Following a failed vision screening in second grade, I was prescribed
bifocals (plano with a +.75 add, to start) which were supposed to
prevent myopia. I suspect now that the centers were wildly wrong, and
the fitting was miserable. Wearing them was head-splittingly painful,
but both the doctor and my parents refused to listen to my complaints,
and I was forced to wear them during every waking moment. (I've since
met other victims of that bifocal plus experiment who smashed every
pair of lenses until their parents gave up, but none who tried to live
with them.)

I could not read at all through the bifocal part, but my parents had
been prompted to force me to, so I learned how to sneak one eye just
above the dividing line while still appearing to have my head and book
in the required position. That was just the beginning of a series of
different adaptations to different lenses, with more and more minus on
top, but seemingly no better fit.

Through all of this no one ever explained to me what I should be doing
in order to make the "plus lens" theory work, and nobody ever listened
when I said my glasses hurt my eyes and brain, or didn't fit.

Then hard contacts became available, and the story was they would
prevent myopia, so the bifocals were yanked away along with the
separate space where I had done all of my reading for years, and I
entered a totally different world of visual distortion and poor fit.
By college I ended up -5.25, with miserable oblique astigmatism, and
finally just threw the lenses all away cold turkey.

It has been a long slow process of becoming aware of the visual cues
that were preventing "normal binocularity", and consciously practising
undoing them. For instance, today's exercise has been to force myself,
while turning my head toward the right, to "anchor" myself to the
earth via the image in the part of my right eye's field of view that
is blocked from the left eye by my nose.

While wearing negative lenses, the view through the binocular part of
my field of view was tiny relative to my peripheral vision, so a small
head rotation caused a lot of "world space" to disappear behind my
nose quickly. When it re-appeared outside the lenses and behind my
nose in the peripheral area it was much larger and slower-moving (in
the angular sense), but I knew it was the same scene and learned to
"create mental space" to take up the difference. (Eventually I created
so much of this space that the nose boundaries were projected to
infinity, and then beyond infinity. I lived most of my life feeling
like I had backed out of the universe, back through the last shell of
a pre-Copernican heaven, and the universe was contained in a roughly
four foot bubble suspended in front of my eyes.)

For most of my life the trustworthy edge of the peripheral boundary
formed by my nose was the binocular side - the peripheral side was
like a "space pump" where the sizes and angular dimensions of objects
were completely flexible. So today I've been learning to mentally hold
the size of objects in my right peripheral view constant as they
approach and then appear beyond the nose boundary in binocular view.
The experience is still unsettling, somewhat on the level of an LSD
trip. Learning to hold the left side "solid" was comparatively easy.
To make this remaining side solid I am forced to resolve my sense of
the size and location of my own body.

I'm reminded of the discussion in some of the later replies about
catching a ball. Early in my adventures in lens wearing, the issue
with ball sports was just to be able to track the ball fast enough in
the trustworthy central binocular vision area to know where the ball
was. As my sense of peripheral space became more disconnected from my
central vision, the issue was more with feeling where my body was in
relation to the ball and the ball field. I could tell where the ball
was relative to the other players, but its relation to my own body was
about as real and immediate as that of a ball on television. My body
didn't even feel like it was on the same field.

No, none of this has been measured clinically. I'm not sure it even
relates to anything the optical professions measure. When I abandoned
lenses and started my self-directed journey, I thought the problem was
with my eyes. Now I'm convinced it is much deeper in my brain, and
bordering on metaphysics.

Loren

No simple answer, but best characterized as this: something tossed to
me, with a decent amount of arc and minimal velocity: good chance of
catching it;

A line drive: I'm getting beaned ... a virtual certainty.

One of the issues that may come heavily into play: your alignment may
have been =stable= since just post-operative.  In my case, the
strabismus is nonconcomitant (varying in every direction in which I
look) AND has been altered with the three surgeries that I've had, with
vision therapy interventions, AND with age.  So ... the neurologic
whatever-it-is that handles these issues probably never had enough
stable data to develop the right algorithm.

I seem to recall that you could say--with some certainty--that a person
whose eyes turned OUT nearly always threw the ball (say: basketball)
short of the hoop, while a person whose eyes turned IN nearly always
over-threw the ball.

Something like that....

As I'm going exo- now, AND working my way into presbyopia ... with my
accommodative issues .... I'm looking into VT once again to try to
stabilize the angles.

This one eyed person can't even reach out for a door handle and get it
first time.  Don't you have problems like that?  I can't shake hands
with anyone properly either.  I just hold my hand out and make them do
the finding, it works better that way.

I have also found that it isn't quite true that stereoscopic vision
isn't used at distance.  Many times I can't tell where something is in
relation to something else while nobody else seems to have quite the
same problem.

Ann