Zenny update, Feb 27, 2012
 

Went back to the independant eye professional, not a Walmart employee. She
put me on the gadget, and dialed in some correction. When she finished, I
glanced at the numbers on the front of the dial a focuss. And they were the
same numbers as my prescription from 2007.

I'll admit, I'm puzzled. My year 2007 eye glasses aren't strong enough. They
sure don't behave like the dial a focuss eye gadget did. I had another pair
of Zennis, which the other optician checked, and finds it's the same as my
2007 prescription. Those were not strong enough.

Do glasses change their focusss over the years? Does the focuss change, if
glasses are in storage?

Christopher A. Young
Learn more about Jesus
www.lds.org
..

Zenny update, Feb 27, 2012
 

"Stormin Mormon" fired this volley
in :

Do glasses change their focusss over the years? Does the focuss
change, if glasses are in storage?

No, Stormy, not unless they're plastic, and you get them _really_ hot...
and then they "warp"; they don't change focus 'gracefully'.

There are a lot of vision defects besides gross focus that might be at
play. You might have a very minor astigmatism. You may have a slight
clouding of the vitreous humor or the onset of cataracts. You might have
dried out corneae that makes looking at things like looking through
crinkled cellophane. You might have slight retinal damage from some
bright light or UV incident in the past.

You may also just be a victim of the fact that the eye itself changes
focus slightly during the day, and from times of good hydration to
dehydration.

The humors of the eye are 99.9% water. Reduce the water in your body,
and you change the concentration of water vs. proteins in the humors.
They change pressure, volume, transparency... and you "see" it as
glasses that aren't "strong enough".

I've found that most eye tests end up recommending a lens that is just a
bit too 'strong'. When the image you see goes from clear to SHARP and
more contrasty than before, the correction is too strong. That puts a
burden on the lens muscles. Whatever loss of flexibility you have in the
lens from age is then over-taxing those muscles even harder. They get
fatigued, and you "lose focus" both optically and mentally.

I go from doing long-range work with fireworks to close-up machining, to
CAD, to reading. The only solution I've found that handles all the tasks
well is a pair of glasses for each situation.

LLoyd

Zenny update, Feb 27, 2012
 

Sounds like you have some experience. And, any of those are possible.

I'm not sure what my next step is. At present, I'm planning to order some
glasses a step stronger, from Zenni, and see if they do any better. In every
day life.

I may also end up with different glasses for driving, computer, close work,
etc.

Christopher A. Young
Learn more about Jesus
www.lds.org
..

"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote in message
. 3.70...
"Stormin Mormon" fired this volley
in :

Do glasses change their focusss over the years? Does the focuss
change, if glasses are in storage?

No, Stormy, not unless they're plastic, and you get them _really_ hot...
and then they "warp"; they don't change focus 'gracefully'.

There are a lot of vision defects besides gross focus that might be at
play. You might have a very minor astigmatism. You may have a slight
clouding of the vitreous humor or the onset of cataracts. You might have
dried out corneae that makes looking at things like looking through
crinkled cellophane. You might have slight retinal damage from some
bright light or UV incident in the past.

You may also just be a victim of the fact that the eye itself changes
focus slightly during the day, and from times of good hydration to
dehydration.

The humors of the eye are 99.9% water. Reduce the water in your body,
and you change the concentration of water vs. proteins in the humors.
They change pressure, volume, transparency... and you "see" it as
glasses that aren't "strong enough".

I've found that most eye tests end up recommending a lens that is just a
bit too 'strong'. When the image you see goes from clear to SHARP and
more contrasty than before, the correction is too strong. That puts a
burden on the lens muscles. Whatever loss of flexibility you have in the
lens from age is then over-taxing those muscles even harder. They get
fatigued, and you "lose focus" both optically and mentally.

I go from doing long-range work with fireworks to close-up machining, to
CAD, to reading. The only solution I've found that handles all the tasks
well is a pair of glasses for each situation.

LLoyd

Zenny update, Feb 27, 2012
 

On Feb 28, 10:51*am, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

I've found that most eye tests end up recommending a lens that is just a
bit too 'strong'. *When the image you see goes from clear to SHARP and
more contrasty than before, the correction is too strong.

WHAT?!? Sharpest and highest contrast are what define the word
"focus". Why in the world would you want anything less than the
sharpest focus? How could that make your eye muscles work harder?

I made a fixture for autofocusing a scanner module. The entire
procedure consisted of adjusting the mechanism to produce the highest
peak-to-peak output when looking at a black & white test pattern.
That, by definition was the focus point - whitest whites and blackest
blacks = highest contrast = properly focused.

Zenny update, Feb 27, 2012
 

On Feb 28, 10:51*am, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:
"Stormin Mormon" fired this volley
:

Do glasses change their focusss over the years? Does the focuss
change, if glasses are in storage?

No, Stormy, not unless they're plastic, and you get them _really_ hot...
and then they "warp"; they don't change focus 'gracefully'.

There are a lot of vision defects besides gross focus that might be at
play. *You might have a very minor astigmatism. *You may have a slight
clouding of the vitreous humor or the onset of cataracts. *You might have
dried out corneae that makes looking at things like looking through
crinkled cellophane. *You might have slight retinal damage from some
bright light or UV incident in the past.

You may also just be a victim of the fact that the eye itself changes
focus slightly during the day, and from times of good hydration to
dehydration.

The humors of the eye are 99.9% water. *Reduce the water in your body,
and you change the concentration of water vs. proteins in the humors.
They change pressure, volume, transparency... *and you "see" it as
glasses that aren't "strong enough".

I've found that most eye tests end up recommending a lens that is just a
bit too 'strong'. *When the image you see goes from clear to SHARP and
more contrasty than before, the correction is too strong. *That puts a
burden on the lens muscles. *Whatever loss of flexibility you have in the
lens from age is then over-taxing those muscles even harder. *They get
fatigued, and you "lose focus" both optically and mentally.

I go from doing long-range work with fireworks to close-up machining, to
CAD, to reading. *The only solution I've found that handles all the tasks
well is a pair of glasses for each situation.

LLoyd



I agree with all of what you said here (except the "focus" part [see
my other reply]). I would be very suspicious, however, of an
optometrist who did not check for all of those conditions. They should
all be discoverable during a routine examination. I can't imagine an
"eye test" without checking for astigmatism. If the examiner is only
doing a simple refraction test (is this better than that), you and
Stormy need to find a good eye doc who will check for other problems.
It's a whole lot easier to prevent blindness than to correct it.

Even though I have purchased a set of trial lenses (and I have already
determined that the astigmatism correction in one eye is off by at
least ten degrees, but more on that after I've had some more time to
play), I will still go for an annual checkup at the ophthalmologist.

Zenny update, Feb 27, 2012
 

rangerssuck fired this volley in news:65903f43-
:

WHAT?!? Sharpest and highest contrast are what define the word
"focus". Why in the world would you want anything less than the
sharpest focus? How could that make your eye muscles work harder?


I did not use the word "focus". I used the term "the correction is too
strong".

When over-correction is introduced, the image _appears_ to the patient to
be sharper because it also becomes smaller and more contrasty. EXACTLY
on focus is just before that visual artifact occurs.

Many people choose the over-corrected prescription, only to find later
that their eyes are constantly fatigued.

LLoyd

Zenny update, Feb 27, 2012
 

On Feb 28, 12:29*pm, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:
rangerssuck fired this volley in news:65903f43-
:

WHAT?!? Sharpest and highest contrast are what define the word
"focus". Why in the world would you want anything less than the
sharpest focus? How could that make your eye muscles work harder?

I did not use the word "focus". *I used the term "the correction is too
strong".

When over-correction is introduced, the image _appears_ to the patient to
be sharper because it also becomes smaller and more contrasty. *EXACTLY
on focus is just before that visual artifact occurs.

Many people choose the over-corrected prescription, only to find later
that their eyes are constantly fatigued.

LLoyd



Do you have a reference for that? It just doesn't make sense to me
that something could be more contrasty and less focused.

Zenny update, Feb 27, 2012
 

rangerssuck fired this volley in news:b731d273-
:


Do you have a reference for that? It just doesn't make sense to me
that something could be more contrasty and less focused.

Here's a response from a Florida Optimetrist on the "Optiboard" forum.

It's obviously not a cite to some special authority, but is an agreeing
opinion from a professional in the field.

Ask your own opthalmologist. You'll get the same response.
--------
From: http://www.optiboard.com/forums/show...8-Question-on-
overcorrected-cyl

"A -.25 over correction will not blur him to the extent you are thinking,
unless maybe he's presbyopic. Too much minus gives the pt the illusion of
smaller, darker and clearer (sometimes). Bottom line.....sometimes change
is not easy, but I don't think it will kill the pt. if he wears the old
script :)"
----------

LLoyd

LLoyd

Zenny update, Feb 27, 2012
 

"Lloyd E. Sponenburgh" lloydspinsidemindspring.com fired this volley in
. 3.70:

Here's a response from a Florida Optimetrist on the "Optiboard" forum.

I should have said that this effect is more profound when correcting for
myopia.

LLoyd

Zenny update, Feb 27, 2012
 

On Tue, 28 Feb 2012 09:36:15 -0500, "Stormin Mormon"
wrote:

Went back to the independant eye professional, not a Walmart employee. She
put me on the gadget, and dialed in some correction. When she finished, I
glanced at the numbers on the front of the dial a focuss. And they were the
same numbers as my prescription from 2007.

I'll admit, I'm puzzled. My year 2007 eye glasses aren't strong enough. They
sure don't behave like the dial a focuss eye gadget did. I had another pair
of Zennis, which the other optician checked, and finds it's the same as my
2007 prescription. Those were not strong enough.

Do glasses change their focusss over the years? Does the focuss change, if
glasses are in storage?

Christopher A. Young
Learn more about Jesus
www.lds.org

The development of cataracts can do that, and they don't have to be
very big to affect vision. Cataracts in the central area of vision
will affect vision more than if the changes begin somewhere else in
the lens. When cataracts interfere with vision, the phoropter reports
the best correction for each eye, but it doesn't mean that you can see
20/20. There could be other reasons for that, but this was my
experience prior to having my cataracts out.

RWL