P3D Re: Pulfrich Effect

[Dan Shelley <dshelley@xxxxxxxxxxxx>]

Boris Starosta wrote:
> 
> A number of list members have mentioned 3-d effects upon first wearing new
> prescription glasses.  I've been meaning to post about this as well...
> 
> I just got my first set of glasses a few months ago.  Looking through them,
> I perceive the illusion of depth along bright color gradients.  For
> example, my CD software has this make-believe red LED display, and as seen
> through the glasses, the LEDs appear substantially farther away (sunken
> into the display) than the remainder of the display.  The LEDs are shown on
> a black field.  Same goes for the red LEDs on my otherwise black modem.
> Strange effect.  I detect no other chromatic aberration in the field of
> view.

This has happened to, and been disscussed here before, by others - only
the other way around. Take me for example. I wear special corrective
contacts for a particular degeneration I had a while back. (Kerataconus)
I wear them all day, sometimes 18 to 20 hours a day. This was hard to
get used to at first as these have an extra ridge on them, but you can
get used to a lot if it helps - I have found. All that to get to: I find
that late at night when I just can't stand it any longer, I take them
out and some things on the computer shift in my perception, almost along
the lines of the Chromadepth phenomena. Reds and orages seem to float
above the CRT, and blues and greens seem to recede a bit in to it. 

> A propos the glasses.  I dislike wearing them, because I think they are
> ruining my eyesight!  I got them, despite the fact that I still have
> (marginally) 20/20 vision, because I thought it would make my rather long
> stints in front of the computer a little less tiring (I am farsighted).  I
> was reluctant to get them, because I thought they might accelerate the
> decay of my vision (i.e. the muscles controling the lenses of my eyes would
> be weakened).  Nevertheless, I thought I would give them a try.
> 
> Well, what I feared has indeed occurred, at an alarming rate!  At first I
> would wear them for only an hour or so, because my vision is indeed much
> improved, and I like to see all the details I have apparently been missing
> recently.  Upon removing the glasses, it would then take an hour or so for
> my eyesight to return to "normal."

This is exactly how I felt when my eyes started to go... I was 26, had
perfect vision up to then, but something was happening. It took the
doctors two years to totally diagnose and treat the "disease". During
that time of letting my head muscles get used to not "correcting" my
vision, things seemed much worse. In fact, the first time I went in to
get checked, the guy was shocked I had not been in before as my eyes
were already fairly "damaged". But, my heavy duty freeviewing, etc had
allowed me to compensate for the changes in my eyes a great deal. He
said this was a good thing, but that it would cause problems during the
adjusting to correction phase.

Boris, IMHO what you are finding out is that when you have the glasses
on, you are seeing better, so your head muscles don't have to work so
hard to try to get the best correction that streching and squashing your
eyes can provide. Yes, it feels like the correction is doing "damage",
but it will help a great deal in the long run. I now see better than I
did before, and appreciate detail in treest several miles away. I didn't
remember noticing that before. There was a transition time that was
difficult, but I am very happy now.

> Then I tried wearing the glasses for a whole day - enjoying all the
> textures that I've been missing in the world.  

There is that "tree" thing I mentioned above.

> After that day, I swear it
> took nearly a week for my eyes to get back to "normal."  

I remember this exactly.

> What I mean is,
> that after wearing the glasses, my eyesight is _significantly_ degraded for
> the time periods described.  

Or, your muscles relaxed, and were difficult to re-train to compensate,
combined with your brains new knowledge that what it could do through
muscle manipulation was not as good as what you had just experienced. It
took the week for your brain to think, hey things are normal again - IE
forgetting what the glasses had shown it.

> To the point where I feel I can't function
> without the glasses at all.  Needless to say, this is very disconcerting
> and disappointing to me, as I've always had very good vision - with the
> exception of the slight degradation in recent years.

Welcome to the human race old man! ;-)

The motto of all of this for everyone ont eh list... PRACTIVE
FREEVIEWING and CROSS-EYED VIEWING. It's as good as any other
excercise!! =)

Dan


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