> On Mar 20, 6:35*am, Horus <horus...[at]hotmail.com> wrote:
> > On Mar 19, 11:55*am, Dan Abel <da...[at]sonic.net> wrote:

> > > I've tried that. *I was zero in the right, and -10D in the left. *
> > > First time for me to hear a person who has -10D myopia
> > in the left and 0 in the right. You are kidding right?

> > If you are not kidding. Your unique situation may give
> > researchers clue to whether a single genetic switch
> > can initiate eyeball shape change and learn the trigger.
> > Perhaps you always sleep on the left side or use
> > appliance on the left that could trigger the genetic
> > change that make your left eye abnormal? What
> > other theories do you have why you have perfect
> > right and incredibly high myopic left? Hope you
> > can make meet some eye researchers for your
> > unique situation.

> > > Wearing glasses, it is impossible for the brain to merge the two images,
> > > due to the difference in size of the images. *It doesn't matter what you
> > > do, it cannot be done. *I went through five years of seeing double,
> > > until my brain learned how to just block out one image completely. *I
> > > didn't have this problem with contacts, and so wore them 14 hours a day,
> > > 7 days a week. *This was before the 30 day contacts came out.
> > > > > In most cases, "reducing strain" indicates reducing accommodation.
> > > > Accommodating stimulates convergence and it will still continue to do
> > > > so if
> > > > you make new glasses.
> > > > If you want to reduce accommodation, why not just reduce accommodation? *
> > > Currently you are wearing -7D and -8D to correct your vision at
> > > infinity. *Find out what you need to see at your normal close distance. *
> > > Perhaps it might be -5D and -6D. *

> For what it's worth...
> Horus's IP Address puts him/her in the Philipines.
> I wouldn't rule out this BEING Pia, again, but under an alias.
> Would that surprise anybody, btw?
> Nah....

> You know: the guy who -- in an effort to break from the stain of my
> family's tradition -- occasionally comes to s.m.v., and declares that
> shoes ARE the cause of all myopia.

> I wonder how one can differentiate between glasses that are wrong
> and the eyes having phoria (?) Any particular tests?

> Well. I live in Indonesia. All optical shops can't promise accuracy so
> the vertical displacement is on average around 1-2mm. Since my
> power is high at -8.0. I can't tolerate even 1mm. I want zero vertical
> displacement which no one in the country can deliver.

> However
> you hint that in the US. Eyeglasses are accurately made so I
> wonder where I can order one in the US. Since I haven't
> set foot in your country. I can't just walk in to one. Hence

> "Neil Brooks" <neil0...[at]yahoo.com> wrote
> > Would that surprise anybody, btw?
> > Nah....
> Who are you?
> -MT

> Would that surprise anybody, btw?
> Nah....

> On Mar 19, 11:55*am, Dan Abel <da...[at]sonic.net> wrote:
> > In article
> > <c72c3580-c936-4f32-a582-ad3202f6a...[at]s38g2000prg.googlegroups.com> ,
> > *Horus <horus...[at]hotmail.com> wrote:
> > > On Mar 19, 7:16*am, "Mike Tyner" <mty...[at]mindspring.com> wrote:
> > > My PD is 68 and if I get extra pair made at 65mm. It will be
> > > exclusively
> > > for near use and not far because I have the other glass made at 68.
> > > I thought that there would be less chromatic aberration if I get
> > > one made at 65. So you are saying it's not much and impractical
> > > to make one at 65 and you never made one for any of your
> > > patient because there is absolutely no advantage of any kind?
> > > > > My myopic power is -7.0D on right and -8.0D on left. Does the
> > > > > inbalance power mean the convergence on each eye is different?
> > > Know the relationship of convergence and power. Supposed
> > > a patient had a myopia of only -1.5D at right side and
> > > -8.0D at left side. Can the convergence change? In
> > > this case, how is the optical centers of the lens
> > > adjusted (if at all)? Just want a good theorerical
> > > grasp of relationship between convergence and power.
> > I've tried that. *I was zero in the right, and -10D in the left. *
> First time for me to hear a person who has -10D myopia
> in the left and 0 in the right. You are kidding right?
> If you are not kidding. Your unique situation may give
> researchers clue to whether a single genetic switch
> can initiate eyeball shape change and learn the trigger.
> Perhaps you always sleep on the left side or use
> appliance on the left that could trigger the genetic
> change that make your left eye abnormal? What
> other theories do you have why you have perfect
> right and incredibly high myopic left? Hope you
> can make meet some eye researchers for your
> unique situation.
> Horus
> > Wearing glasses, it is impossible for the brain to merge the two images,
> > due to the difference in size of the images. *It doesn't matter what you
> > do, it cannot be done. *I went through five years of seeing double,
> > until my brain learned how to just block out one image completely. *I
> > didn't have this problem with contacts, and so wore them 14 hours a day,
> > 7 days a week. *This was before the 30 day contacts came out.
> > > In most cases, "reducing strain" indicates reducing accommodation.
> > > Accommodating stimulates convergence and it will still continue to do
> > > so if
> > > you make new glasses.
> > If you want to reduce accommodation, why not just reduce accommodation?*
> > Currently you are wearing -7D and -8D to correct your vision at
> > infinity. *Find out what you need to see at your normal close distance. *
> > Perhaps it might be -5D and -6D. *
> > > > You seem to be saying that your vision would be better if you wore a few
> > > > p.d. of horizontal prism. *Why do you need to alter your vergencedemand at
> > > > near?
> > > As I have said, just to get less eyestrain by reducing
> > > convergence and accomodation when using monitor
> > > 15 hours a day, nothing more. I have no abnormal
> > > phoria.
> > > > What are you trying to fix?
> > --
> > Dan Abel
> > Petaluma, California USA
> > da...[at]sonic.net- Hide quoted text -
> > - Show quoted text -

> In article
> <c72c3580-c936-4f32-a582-ad3202f6a...[at]s38g2000prg.googlegroups.com> ,
> *Horus <horus...[at]hotmail.com> wrote:
> > On Mar 19, 7:16*am, "Mike Tyner" <mty...[at]mindspring.com> wrote:
> > My PD is 68 and if I get extra pair made at 65mm. It will be
> > exclusively
> > for near use and not far because I have the other glass made at 68.
> > I thought that there would be less chromatic aberration if I get
> > one made at 65. So you are saying it's not much and impractical
> > to make one at 65 and you never made one for any of your
> > patient because there is absolutely no advantage of any kind?
> > > > My myopic power is -7.0D on right and -8.0D on left. Does the
> > > > inbalance power mean the convergence on each eye is different?
> > Know the relationship of convergence and power. Supposed
> > a patient had a myopia of only -1.5D at right side and
> > -8.0D at left side. Can the convergence change? In
> > this case, how is the optical centers of the lens
> > adjusted (if at all)? Just want a good theorerical
> > grasp of relationship between convergence and power.
> I've tried that. *I was zero in the right, and -10D in the left. *

> Wearing glasses, it is impossible for the brain to merge the two images,
> due to the difference in size of the images. *It doesn't matter what you
> do, it cannot be done. *I went through five years of seeing double,
> until my brain learned how to just block out one image completely. *I
> didn't have this problem with contacts, and so wore them 14 hours a day,
> 7 days a week. *This was before the 30 day contacts came out.
> > In most cases, "reducing strain" indicates reducing accommodation.
> > Accommodating stimulates convergence and it will still continue to do
> > so if
> > you make new glasses.
> If you want to reduce accommodation, why not just reduce accommodation? *
> Currently you are wearing -7D and -8D to correct your vision at
> infinity. *Find out what you need to see at your normal close distance.*
> Perhaps it might be -5D and -6D. *
> > > You seem to be saying that your vision would be better if you wore a few
> > > p.d. of horizontal prism. *Why do you need to alter your vergence demand at
> > > near?
> > As I have said, just to get less eyestrain by reducing
> > convergence and accomodation when using monitor
> > 15 hours a day, nothing more. I have no abnormal
> > phoria.
> > > What are you trying to fix?
> --
> Dan Abel
> Petaluma, California USA
> da...[at]sonic.net- Hide quoted text -
> - Show quoted text -

> "Horus" <horus...[at]hotmail.com> wrote
> > When testing what you mentioned. Things don't really jump up and
> > down,
> > however they jump left and right when I alternate my hand over one
> > lens
> > then the other. Is this supposed to be normal experienced by all
> > or only a few?
> That's your phoria. It's the same with every pair because it's the way your
> eyes line up, not because your glasses are wrong. A little horizontal jump
> is normal. That's what you meant when you said you have no abnormal phoria.

> > Anyway. Where in the United States can I order online where
> > I simply give them the prescription... where they make perfect
> > spectacles with zero horizontal jumping and the PD exactly
> > dead on? Laboratory so accurate that the glasses are almost
> > MilSpec. Any such place?
> You want extreme technical accuracy from an online retailer. I want a new
> boat.

> I doubt either of us will be satisfied very soon.
> -MT

> When testing what you mentioned. Things don't really jump up and
> down,
> however they jump left and right when I alternate my hand over one
> lens
> then the other. Is this supposed to be normal experienced by all
> or only a few?

> Anyway. Where in the United States can I order online where
> I simply give them the prescription... where they make perfect
> spectacles with zero horizontal jumping and the PD exactly
> dead on? Laboratory so accurate that the glasses are almost
> MilSpec. Any such place?

> "Horus" <horus...[at]hotmail.com> wrote
> > But you said accomodation and convergence are wired together
> > and changing one can change the other.
> Clear vision is an equilibrium, a balance between convergence and
> accommodation. Equilibrium is a balance that can tip either way.
> > So if you reduce
> > convergence, you reduce accomodation.
> If you "assist" convergence, some people lose focus.
> > *But you said
> > that in eyestrain, one must reduce accomodation.
> No, I said most "eyestrain" is accommodative, not phoria-related. *IOW
> focusing (accommodative) problems are more common than convergence
> (diplopia) problems.
> Convergence is seldom treated with prism (by decentration or otherwise) when
> there is a normal phoria and no diplopia.
> > However
> > we can reduce convergence and hence reduce accomodation.
> That's right. Thing is, if you hold a book at 40 cm and _reduce_ your
> accommodation, THE PAGE GETS BLURRY.
> > Unless you mean there is a way to reduce accomodation
> > without reducing convergence? *How?
> Add +0.50 to your prescription. Most of us wouldn't adjust the PD when doing
> that.
> > Of course I have eyestrain daily when using computer 15 hours.
> > I just want to know ways to eliminate it by altering the glasses.
> Have your phoria tested. If it's normal, have glasses adjusted by +0.50 and
> quit worrying about prism.
> > It doesn't make sense to induce more base-in to converge less
> > by making the optical centers wider than the PD? I still
> > can't see the reason why it can't be done.
> Because near work gets blurry when you reduce accommodation. If you reduce
> the need for convergence, you usually must reduce the need for accommodation
> by incorporating plus lenses.
> OTOH converging assists accommodation, so if someone doesn't accommodate
> well, we might INCREASE the demand for convergence, to boost accommodation.
> > It's not commonly
> > done in the 1980s but with computers now becoming
> > part of our life and we using it 15 hours daily. We ought
> > to think of it.
> Not as you imagine.
> Until computers, 20 years ago the "nominal reading distance" for near vision
> was 16 inches. For grandma reading her Bible, that's about right.
> Now Gramma has a PC and a Wii and wants PC glasses that are clear at 24".
> > It's off by 0.5mm to 1mm. Is this allowance normal
> > in automatic eyeglass making machine or are certain
> > machines more accurate than others? In your machine,
> > can you produce 100% fully vertically centered OC,
> > that is, without *any 0.5mm-1mm off in the vertical
> > axis of the optical centers?
> Maybe things are different there, but I thought people made those
> placements, not machines. Anyhow...
> Test your phoria. If you don't have vertical phoria at the reading position
> in your glasses, the placement is fine. If you do have significant vertical
> phoria at your reading position, it'll get tiresome pretty quick and you'll
> want to ask for a remake. Wear them in, show the optician "things jump up
> and down" when you alternate your hand over one lens then the other.

> If the OCs are _perfect_ you can still always show vertical phoria in
> certain positions because your lenses aren't the same left and right. *Don't
> evaluate at the OCs. Evaluate your phoria at the position you read through.
> -MT