General forum visual science

**drk** · 05-04-2010, 02:00 PM

On a more serious note, I'm trying to start a community project, here.

I have tended to lump progressive non-adapts into the category of "progressive non-adapts". Not very specific.

I'm trying to analyze what patient factors are involved patients non-adapt with the goal of getting them into the next best thing.

Here's what I have so far:

Category 1: Non-adapt due to problems with orthoscopy. http://www.medterms.com/script/main/...rticlekey=7270

Category 2: Non-adapt due to problems with zone areas.

Does anyone have any contribution, please?

**Chris Ryser** · 05-04-2010, 02:42 PM

Non adapt due to:

History of wearing Bifocals

Size of frame

age problems

cost factor

and many more

**drk** · 05-04-2010, 02:44 PM

Thanks, Chris.

**Uncle Fester** · 05-04-2010, 02:57 PM

Category 3: Ryser Equation

**ih8wlmrt** · 05-05-2010, 01:25 PM

non adapt due to crazy/unstable/unreasonable/unsatisfiable(is that even a word?)

**Chris Ryser** · 05-05-2010, 02:20 PM

I have stated that before, that in the earkly days of the progressives, then called "Varilux" the originators SL today the big E, gave courses to opticians in Europe how to fit and also to whom NOT to sell progressives.

When they hit North America with the product and there was at the beginning a general ant-feeling against these distorted lenses, they came up with their non adapt warranty which kicked of sales. There was no risk to the retailer and it progressed where it is today.

While in Europe opticians really checked out a patient if they were a good case for progressives because they did not want to get stuck with a non adapt, on this continent it is a full out battle to sell as many as possible, with no risk involved.

One thing we should not forget that these lenses all come out of a mold that will take the next lens when done, same process as a single vision lens, but a different price.

**uncut** · 05-05-2010, 07:55 PM

drk:
non-adapt due to medical conditions, i.e. musculoskeletal, medications
also occupational contraindications..as in masonry, carpentry-specialized
The second suggestion could also be classified as refusal to buy occupational products...I often find people expect a progressive lens to do EVERYTHING!

**LandLord** · 05-05-2010, 08:09 PM

Most common non adapt problems,
1. Improper expectations
2. Poor candidate, (ie good UCVA)

**braheem24** · 05-05-2010, 09:03 PM

Only non-adapts are the ones that dont want to try another design.

Get familiar with a few lenses that offer the basics:

Wide distance
Wide intermediate
Wide near

Hard designs for sharper vision
Softer designs for comfort

Even Chris wears a PAL.

**drk** · 05-05-2010, 09:29 PM

Originally Posted by braheem24

Hard designs for sharper vision
Softer designs for comfort

That's my type I and type II patient profile.

I guess that's it, then.

**Strab** · 05-06-2010, 08:31 AM

Originally Posted by drk

I'm trying to analyze what patient factors are involved patients non-adapt with the goal of getting them into the next best thing.

Here's what I have so far:

Category 1: Non-adapt due to problems with orthoscopy. http://www.medterms.com/script/main/...rticlekey=7270

Category 2: Non-adapt due to problems with zone areas.

Does anyone have any contribution, please?

I think the most important overlooked aspect of fitting a new presbyopia pt. is failure to observe the pt.'s natural tendencies i.e. head movers vs. eye movers. Of course there are many other factors to consider but I feel this one is overlooked the majority of the time.

**drk** · 05-06-2010, 08:47 AM

Thanks, strab; that's a good point.

Head movers would do better with softer designs: less swim as they move their heads, and they can bring the narrower zones with them.

Eye movers would be more static, and would expect wider zones of clear vision. Harder design.

Now the $64,000 question: Without the space ship Ispseo, how do we observe/ascertain who is who?

Click image for larger version.

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**uncut** · 05-06-2010, 10:42 AM

May I start?
Rx behavior....low myopes and hyperopes-eye movers. mid-range...mixed possiblities depending on 180 powers. High myopes and hyperopes-head turners

**drk** · 05-06-2010, 12:47 PM

See, that makes some sense, if one were to assume that "eye-turning" is natural, and the earlier onsetting ergo higher refractive error patients have been "trained" to use the optical centers or suffer off-axis blur/prism/etc.

And it works this way, too: higher power lenses have worse off-axis performance, so you'd want the clearest, widest zones to not compound the issue.

So, the basic idea: "Hard prescription/Hard design. Soft prescription/Soft design."

**Chris Ryser** · 05-06-2010, 12:56 PM

Originally Posted by braheem24

Even Chris wears a PAL.

Correction.................Only on special occasions, and it only starts becoming comfortable after the 2nd or 3rd Scotch. :bbg:

**uncut** · 05-06-2010, 01:00 PM

Scotch/rocks.......ROCKS!

**LandLord** · 05-06-2010, 04:11 PM

Originally Posted by uncut

Scotch/rocks.......ROCKS!

Why would you ruin the taste of scotch with ice?

**braheem24** · 05-06-2010, 04:26 PM

Opticians have such a small attention span, God help us.

**LandLord** · 05-06-2010, 04:39 PM

Oh, yeah, the thread. Sorry.

"I'm trying to analyze what patient factors are involved patients non-adapt with the goal of getting them into the next best thing."

Patient factors?
Again, I think it's unrealistic expectations, and good UCVA that causes most non adapts.

**OpticalMessiah** · 05-06-2010, 05:01 PM

LandLord,
By "unrealistic expectations", are you including patients who think that a PAL can solve all visual needs?
I'm just checking.

**LandLord** · 05-06-2010, 10:32 PM

Yes, that would qualify as unrealistic.

**Darryl Meister** · 05-11-2010, 06:32 PM

Just as a point of clarification, "orthoscopic" in optics, at least, generally pertains to the distortion of the shape of an image produced by a lens. A phrase like "correct vision," on the other hand, is potentially ambiguous. You can have a clear image that is not orthoscopic or a blurred image that is orthoscopic, although neither is particularly desirable.

Progressive lens non-adapts may be the result of a large number of factors. In no particular order of importance:

1. Lens design, including the management of both surface and oblique astigmatism.
2. Add power, since surface astigmatism is proportional to it.
3. Patient sensitivity to vertigo, since peripheral image swim is present.
4. Incorrect spectacle refraction or power errors (e.g., not prescribing the full cylinder).
5. Incorrect fitting or incorrect centration of the lenses.
6. Poor adjustment of the frame.
7. Inadequate patient education in the proper use of the lenses.
8. Unreasonable patient expectations regarding performance.
9. Patient prescription (e.g., oblique cylinders are more problematic optically).
10. Pupil size, although in some cases this can actually improve vision as well.
11. Blocking waves or other surfacing aberrations.
12. Poorly motivated patient or patient with buyer's remorse.
13. Patient with significant binocular vision dysfunction.
14. Miscellaneous optical factors like vertical imbalance, reflections, chromatic aberration, etcetera.

I'm there are other factors as well, but those come immediately to mind.

**drk** · 05-11-2010, 08:20 PM

Thanks, everyone.

I'm looking for the correct term for the property of "less swim" or "less distortion". I guess "orthoscopy" is not perfect.

**Darryl Meister** · 05-11-2010, 10:11 PM

I'm looking for the correct term for the property of "less swim" or "less distortion". I guess "orthoscopy" is not perfect

I think "less (image) swim" and "less (skew) distortion" work rather well. "Orthoscopy" is the complete absence of distortion. But my point was that a lack of distortion doesn't necessarily imply "correct vision," since you could still have a blurred image.