On 4/23/07 7:49 PM, in article f0jr6t$5fo$1[at]reader2.panix.com, "David Combs"
<dkcombs[at]panix.com> wrote:

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lens,

Bill
-- Fermez le Bush--about two years to go.

On Apr 23, 10:49 pm, dkco...[at]panix.com (David Combs) wrote:
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Yes. Using a pinhole is a quick way to discover if refraction is the
problem. With a urgent case that presents with a patient complaining
of recent onset blurred vision, if he pinhole doesn't help then the
doctor knows not to waste time doing a refraction.

Judy

In article <1176229611.581985.115030[at]y80g2000hsf.googlegroups.com> ,
Dr Judy <mpace99[at]rogers.com> wrote:
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Question from mere layman:

"if vision improves with a pinhole":

Question: what effect from a pinhole?

(All I know about pinholes (what, f-stop 500 or more?) is that
you get huge depth-of-field. Like, with that, you don't need
any glasses at all! (that is, just plain magnifying or
the opposite ones))

Is that the effect that's used in the "pinhole test"?


Thanks,

David

On 4/11/07 7:40 AM, in article 461ce715$0$16361$88260bb3[at]free.teranews.com,
"Ron" <no_one[at]home.com> wrote:

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I'll preface by saying that I am not a health professional. But it is not
necessary a genius to grasp what is most likely to be going on. You need the
pro to make sure that it is not something weird that is unlikely.

As the cataract forms, it is likely that different parts of the lens will
have changes in index of refraction. The result is that the (crystalline)
lens is no longer a lens but has multiple separate lenses added to it. That
is what gives the multiple images. Moving the pinhole selects which of these
lenses form possible overlapping images on your retina.

Chances of your vision improving spontaneously is like bucking the second
law of thermodynamics. Your lens will change but probably for the worse.

Bill
-- Fermez le Bush--about two years to go.

"Salmon Egg" <salmonegg[at]sbcglobal.net> wrote in message
news:C241CE7B.6EEB8%salmonegg[at]sbcglobal.net...
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As a closing remark, I would like to remind you that my personal experience
with the pinhole gives me the following:

At first it would improve my vision, reducing the double vision to normal.
HOWEVER, after using it more, I could see that there was a vague line
running from lower right to upper left, and if I would move the pinhole
slightly the object would literally JUMP across the vague line, from the
left side to the right. And if I were to look at a word like 'spelling',
the first few letter would appear in the left lower half, and the rest of
the word would appear in to upper right, slightly ABOVE the letters in the
left side. Its no wonder I am having trouble trying to read.

I found that if I were to make the pinhole smaller, then draw the hole
slowly away from my eye, I could actually focus on something that appeared
to be a microscopic view of water on a slide, and there was a black object
running from the 5 o'clock position to the center with a slight tip off
toward the left at the center. I have referred to this as a 'blackbird'
because of its shape & color. When I rotated the card the 'bird' did not
rotate with it, but objects viewed would jump across the 'body', or up and
down across its 'head'. One last observation is that if I move the hole
around my focal point (peripheral) I can still see the 'bird', unmoving in
the hole, still black, and still shaped like a perched bird.

I took this information to my doctor, assuming it was of value in his search
for a cause. I still don't know where the object I see is located, thinking
that if anyone knew, it would help narrow the search for the cause. I
believe this is a real object, not a result of strange things caused
mysteriously. As with Bill, it allows me to actually separate and see the
two (or three) objects that destroy my normal vision.

Several of you tend to think this is being caused by a cataract, and if left
unattended, could go away as the cataract grows. This option would eliminate
the risks that go along with surgery. However, with today's advanced
technology in cataract surgery, this may be the way to go. I just don't
want to risk losing vision in my 'good eye'.

I appreciate your interest, experience, and expertise, Ron


--
Posted via a free Usenet account from http://www.teranews.com

On 4/10/07 11:26 AM, in article
1176229611.581985.115030[at]y80g...oglegroups.com, "Dr Judy"
<mpace99[at]rogers.com> wrote:

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That is crazy! When cataracts were formed in my eye, pinholes did improve my
acuity. Maybe pinholes are not useful long term, but with a pinhole I could
usually select one of the multiple traffic light images I could perceive
without a pinhole.

Bill
-- Fermez le Bush--about two years to go.

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If the macula is elevated (say due to some neovascular problem),
then usually the lines are bent (standard optics). It may be that in
this process lines get paralleled and appear "doubled". But what I
mean is the _same_ (input) line viewed twice. Maybe the "standard"
Amsler grid should have alternating colors in the grid. That would
help in the differing of lines "doubling" vs lines being crowded
together.

Don W.

PS. Just our of curiosity, just why isn't there a prescribed best fit
Amsler grid? One that can optimize the patient's response to his
problem??

Dr Judy wrote:

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better to say "...then you know there is a refractive component to the
problem".


w.stacy, o.d.

On Apr 10, 1:14 am, Salmon Egg <salmon...[at]sbcglobal.net> wrote:
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In your case, cataract was causing the multiple images. Cataract is
not the sole cause and observations through a pinhole will not
differentiate between corneal. retinal or lens problems.

Dr Judy

On Apr 10, 1:30 am, "Don W" <dwil...[at]prodigy.net> wrote:
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A doubled line could be due to elevation in the macular area. The
Amsler Grid does not diagnose the nature of the retinal problem, it
simply provides evidence that the vision is disturbed and then your
eye doctor needs to investigate exactly what is wrong.


Dr Judy

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