In article <1188627218.868484.291340[at]50g2000hsm.googlegroups.com> ,
andrewedwardjudd[at]hotmail.com wrote:


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Haven't tried reduced. Have tried increased. There's a measurement
using soundwaves that documented it. Don't know how much. Not my job.
It was caused by a buckle.

<andrewedwardjudd[at]hotmail.com> wrote

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Yes, I guess it never happened. I just imagined it.

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I didn't say "thinning." I said "flattening." That's what I read.

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I've never heard of it.

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Go find some.

-MT

<andrewedwardjudd[at]hotmail.com> wrote

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Color fringes only occur off-axis.

I guess that filtering mechanism shuts down when I look through cheap
binoculars, because I sure see fringes then.

-MT

On Sep 1, 4:08 am, "sci.med.vision" <mtyne...[at]gmail.com> wrote:
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By your definition what you have described is Mush. How does that
feel?

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Mighty mush then presumably by your own definitions.


*but* I am prepared to accept and file away in my mind what you have
said and see how it can fit into my model of vision problems. It
certainly has its place there.

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Seems strange there are not more studies on this effect.

I think there is more information available on the puzzle of myopia
than seems currently available which could easily be found with a few
well designed studies.

Is it **only** lens thinning? I wonder if that is an assumption that
fits an already decided belief about myopia?

Corneal curvatures also vary do they not?

Is it really true that no person ever records reducing axial length
ever? What is the highest ever recorded case of reduced axial
length? Is it really Zero??

Is that absolutely proven? Really??

Or is it the case really that there is no data? Really??

Andrew

On Sep 1, 4:32 am, "sci.med.vision" <mtyne...[at]gmail.com> wrote:
But chromatic abb (at
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Mike

You are not seeing this accurately.

1. You need to see that the chromatic abberation is bigger than you
realise. Please look that up.

2. Correct we dont see color fringes

3. Correct band pass filters dont dramatically improve vision

Please reread my last post on this.

You are making an assumption that because your human mind does not
show you colour fringes that there are no colour fringes on the
retina.

It is more complicated than that.

Something happens to the *processing* of the data between the time it
is **sensed** to the time you as a human are aware of it as a
**perception**

Andrew

On Aug 31, 3:31 am, andrewedwardj...[at]hotmail.com wrote:

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I'm not sure it's as much as 2D. But the bichrome test only deals with
the point where a red target and a green one differ, and that's
usually just a quarter-diopter.

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You might think that. But blur is a lateral phenomenon - distinct
points are spread into lower-contrast puddles of blur, spreading out
into the receptive fields of several neurons. But chromatic abb (at
the visual axis) spreads the image fore and aft of the retina, not
sideways. Otherwise there'd be color fringes around everything.
Evidently this doesn't produce as much blur as you think, otherwise
vision would improve dramatically with single-bandpass filters.

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I don't know about that. But I know that if you're talking about the
best visual acuity, you better stick to the macula.

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TV cameras have chromatic aberration also. Simple telescopes and
binoculars have oodles of it. It doesn't translate directly into
lateral blur.

-MT

On Aug 31, 2:40 am, andrewedwardj...[at]hotmail.com wrote:

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No, I've never seen it in print. I've only observed it several times.

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Since I've never seen it published, I've never seen any speculation
about why.

I've read that the general trend toward hyperopia (confirmed by a
documented shift in population averages) is due to gradual flattening
of the surfaces of the lens. Why it would accelerate during major
illness, I have no idea.

-MT

On Aug 30, 4:04 pm, "sci.med.vision" <mtyne...[at]gmail.com> wrote:
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It says chromatic aberration 1.25-1.5 D

It means that readings of refractometer using
monochromatic red light should be different
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.. If the sharp image is "somewhere it the spread", it means
That we do not really know what is error in
Refractometer measurements . Look like more than 1.5 D.
???
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Best acuity with yellow means that we can see through yelow better
than through
blue or red monochromatic filter, provided ( If someone look through
blue or red)
that through blue or red we can not see match under the regular light
conditions . (filter diminish intensity
and gradient on the edges).

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Mike

I already know that.

And you and I therefore already know that:

1. The human eye disperses white light into its component colours
since it has no correction for chromatic aberation and the dispertion
in the visible area is at least 2D.

2. We know that a simple single colour environment does not have
much
influence on the acuity we have. (unless we are slightly myopic when
it makes quite a difference to be in a room lit by a red light - it
seems noticably clearer)

3 We know a human being experiences good colour vision.

So how is that possible?

I can think of two possibilities which might work together or
separately.

1. The brain could select a particular cone type and construct
a clear image from that and *then* add back in the colour to the
clear
image that was created to create the illusion of retinal clarity so
that the retinal image matches the reality of what is being *sensed*
outside the eye.

2. The human eye is most sensitive to yellow which 'just happens' to
be the middle of the colour range. So although we are not aware of
mostly seeing yellow that is what we mostly receive in the brain.
The brain can then add the true colours back in via a learnt process
or something innate.

Pure speculation of course but to argue there is a clear image on the
retina is i think just wrong.

If you close your eyes and get a friend to place coloured objects in
front of you either side of your direct vision it is surprisingly
difficult to accurately say what the colours are until you have
actually moved your eyes to look at them. At that point the colours
become obvious to you.

And i have fiddled with bichrome and trichrome type tests with pure
colour diodes with tiny black crosses on them as tests of my most
best
clearest distance vision.

The visual brain is an amazing thing because we dont really see what
is on the retina or what is outside of ourselves. In nature in fact
there is no colour. Just colourless energy. Colour is our
interpreation of different energy levels.

We imagine or construct what we see and make it something wonderful
(or not).

What we see is only what we imagine is there based on how well each of
us can sense what is there.

Good vision involves good and accurate perception rather than some
automatic process that forces us to see what is only on the retina.
There are no colours on the retina. It is just energy.

Our humanness says there are colours but in reality there are none in
nature.

The sky is not blue. It is just our perception of that range of the
EMS that we call visible light. It is just energy that we can
sense is there.

Our vision is more of a sense than it is like a TV camera set up..

Andrew

On Aug 31, 9:04 am, "sci.med.vision" <mtyne...[at]gmail.com> wrote:

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Mike

I already know that.

And we already know that:

1. The human eye disperses white light into its component colours
since it has no correction for chromatic aberation and the dispertion
in the visible area is at least 2D.
2. We know that a simple single colour environment does not have much
influence on the acuity we have. (unless we are slightly myopic when
it makes quite a difference to be in a room lit by a red light - it
seems noticably clearer)

3 We know a human being experiences good colour vision.

So how is that possible?

I believe that the brain can take a particular cone type and construct
a clear image from that and *then* add back in the colour to the clear
image that was created to create the illusion of retinal clarity so
that the retinal image matches the reality of what is being *sensed*
outside the eye.

Pure speculation of course but to argue there is a clear image on the
retina is i think just wrong.

And i have fiddled with bichrome and trichrome type tests with pure
colour diodes with tiny black crosses on them as tests of my most best
clearest distance vision.

The brain is an amazing thing.

Andrew