help with a fitting

[disoon]

Hi there,

I have a situation with a patient that I'm hoping someone can help me with. This px has had problems in the past adapting into other lenses and can only wear zeiss GT2 lenses well. We did up a new pair of lenses for him in the GT2 and his complaint now is that his right eye is blurry towards the right side. Now from dotting up the markings, I can see that the markings are not parallel but slanted like they had twisted around when edging and/or someone had blocked the lenses incorrectly prior to edging (on the right lens). My question is would this twist in lens cause the px's reading vision to become blurry on the right field of vision? The BC's are the same, we did not change it at all.

Are there any other considerations that I should be looking at. The only other thing that I changed was the seg heights. One pupil is slightly higher than the other so I made one seg 1mm higher.

Please help!! px put the frames on and said that he was seeing well, I turned away for 5 minutes and suddenly he's disgusted and complaining that he's getting a headache and can't see anymore.

Thanks for your inputs.

D

[Robert Martellaro]

Hi there,

I have a situation with a patient that I'm hoping someone can help me with. This px has had problems in the past adapting into other lenses and can only wear zeiss GT2 lenses well. We did up a new pair of lenses for him in the GT2 and his complaint now is that his right eye is blurry towards the right side. Now from dotting up the markings, I can see that the markings are not parallel but slanted like they had twisted around when edging and/or someone had blocked the lenses incorrectly prior to edging (on the right lens). My question is would this twist in lens cause the px's reading vision to become blurry on the right field of vision?

Yes, if it's off more than two degrees (Z80 standards are plus or minus two degrees). Moreover, if the temporal side is high, you might get some blur on the distance gaze (off -axis) as well.

[HarryChiling]

Absolutely the reading would become blurry, the inset changes if you twist the lens and the patient may be lookign through areas of the lens that are unuseable. Plus it seems to be a newer design thing that progressive manufacturers are doing but they try to keep the major errors low and peripheral in the lens especially on shorter corridor lenses assumeing that if fit low they will cut out these areas, but if you twist these particular areas could be coming more and moe into the patients area of vision.

[Barry Santini]

Yes, if it's off more than two degrees (Z80 standards are plus or minus two degrees). Moreover, if the temporal side is high, you might get some blur on the distance gaze (off -axis) as well.

Robert, with respect to your point about ANSI axis tolerance, how do you feel about refractionists who tell patients that a (5 degree) axis change is "too little to change your prescription"

For these cylinder powers, almost *every* refractionist will say this.

???????

Barry

[Robert Martellaro]

Barry,

Sorry it took so long to respond- it was a busy, but profitable day.:)

The docs tend to be a little conservative sometimes, probably trying to save their clients a few bucks. I have a trial lens set, so I can show the client the change in vision; I'd guess they get it right about half the time, although a good percentage of the half who didn't see an improvement still needed new glasses for other reasons; e.g. degraded lens surfaces, worn, unreliable frame, etc., which the doctors fail to consider when they tell their client "you don't need new eyeglasses". What they should say is "your Rx change is insignificant", and as I stated before, even that statement is accurate only about half the time.

[Barry Santini]

Sorry it took so long to respond- it was a busy, but profitable day.:)

Jealous!!!

I'd guess they get it right about half the time, although a good percentage of the half who didn't see an improvement still needed new glasses for other reasons; e.g. degraded lens surfaces, worn, unreliable frame, etc., which the doctors fail to consider when they tell their client "you don't need new eyeglasses".

What they should say is "your Rx change is insignificant".

Absolutely Wonderful!!

Great post, Robert!

[optifocus]

Yes, if it's off more than two degrees (Z80 standards are plus or minus two degrees). Moreover, if the temporal side is high, you might get some blur on the distance gaze (off -axis) as well.

I agree to Robert Up to certain extent. One can't clear in that way. Blurring is natural at some cases..

[rdcoach5]

Show the pt. the axis change with a cross cylinder. Then he will or won't see much difference. Have the pt use both eyes while you're holding the Cross to show the change.

[Freedom]

If lens twist or it not pararell.

Near pd will change more than distance pd .... the distance vision little
effect ... BUT more and much more effect at intermediate and near zone.

The progression line will change ... progress line is mean : corridor line that from fitting cross to near circle ... it convergence

when progression line change ... it effect to visual field for each zone
esp. intermediate

the visual field will narrow than standard. intermediate and near zone
area of clear vision is narrow

Binocular vision is effect too.

Blur vision in one side of view is the RESULT.

Conclude... you must reorder new lens.