Autograph II *SV* fitting instructions

[Laurie]

Hello Again,

Chris, your email got fast attention! The response was forwarded to me, and copied here:

The response below is from Dani Katzman, lens engineer Guru, and the
R & D team at Shamir Israel:

1. In our design philosophy, we made balance between optical properties of the lens and simplicity of the lens fitting process.
2. According to our approach the design pole is always in front of the pupil (defined as the midpoint between the engraving marks).
3. Our approach enables full control of the prism at the PRP (in front of the pupil) no matter if the prism is a thinning prism or prescribed prism.
4. In order to enable simplicity of the fitting process (no need to practice Martin’s law), we designed the lenses to perform well in pantoscopic tilt range of 0.0 to 12.0 degree.
5. At this design generation, we decided not to implement prescription compensation.

Regards. Dani

[HarryChiling]

4. In order to enable simplicity of the fitting process (no need to practice Martin’s law), we designed the lenses to perform well in pantoscopic tilt range of 0.0 to 12.0 degree.

That doesn't make sense.

[drk]

You must admit, it's simple. :hammer:

I take it to mean that it's not POW compensated, at all.

I think we have meridian-optimized curves on this thing, and that's "all".

[HarryChiling]

You must admit, it's simple. :hammer:

I take it to mean that it's not POW compensated, at all.

I think we have meridian-optimized curves on this thing, and that's "all".

You got it, it would be cheaper and simpler to offer an atoric from resolution. I would love to see it optimized more or at least an option for that, the prism thining and the OC being specified does make for a interesting approach to fitting though, I gotta say I like that they incoporate this into their manufactureing of the lens. Seems like they're rushing a product to market, the engravings on it, the thinning, all seem indicative of a Auto progressive with a plano add.

[Barry Santini]

Thanks for the clarification, Laurie. It's pretty consistent with my opening observations

Barry

[Laurie]

...

Keep It Simple Sweetheart?

I can just add, that, over the last two years, traveling ALOT around the US and trying to educate ECP's in regard to fitting OC according to Martin's rule of tilt...

Very difficult to get the message to the masses.

I think that fitting heights (like pals) makes more sense.

If the optician chooses to delegate the vertical OC height instead, the optics should be in the same range, and the OC will be below the datum line, with the MRP/PRP in front of the pupil.

And the beat goes on,

: )

Laurie

[Robert Martellaro]

1. In our design philosophy, we made balance between optical properties of the lens and simplicity of the lens fitting process.

It would have been much less of an optical compromise and still easy to fit, if it was fit like a PAL: Fitting cross 4mm above the 180 line. That would place the OC about midway between the top and bottom on most properly fit frames, which would also eliminate the need for prism thinning.

4. In order to enable simplicity of the fitting process (no need to practice Martin’s law), we designed the lenses to perform well in pantoscopic tilt range of 0.0 to 12.0 degree.

The only way for that to work is to incorporate prescription compensation. For example;

Vertical OC center pupil
A. -5.00DS with 12 panto- surface -4.72 -.21 x 90
B. -7.50DS with 12 panto- surface -7.07 -.32 x 90
C. -10.00DS with 12 panto- surface -9.43 -.43 x 90

5. At this design generation, we decided not to implement prescription compensation.

[HarryChiling]

It would have been much less of an optical compromise and still easy to fit, if it was fit like a PAL: Fitting cross 4mm above the 180 line. That would place the OC about midway between the top and bottom on most properly fit frames, which would also eliminate the need for prism thinning.



The only way for that to work is to incorporate prescription compensation. For example;

Vertical OC center pupil
A. -5.00DS with 12 panto- surface -4.72 -.21 x 90
B. -7.50DS with 12 panto- surface -7.07 -.32 x 90
C. -10.00DS with 12 panto- surface -9.43 -.43 x 90

Great points Robert, my guess woud be that this lens was a feeler to see if the market would accept this type of product. I think it definately will so for the time being when ordering the lenses keep in mind that the lenses do not incorporate POW so the calculations must be done on the opticians end. This is actually a good thing as it will still allow an optician to differentiate themselves through knowledgeable fitting skills.

[Barry Santini]

Since you were so efficient at getting answers from Shamir on Panto range questions, could you:

Find out what range of face-form (dihedral) values are also considered by Shamir to be acceptable? For instance, based on the range indicated for pantoscopic tilt, I'm thinkin' 0 to 8 degrees, yes?

Thanks in advance!

Barry

[Robert Martellaro]

...When there is panto (almost 100 percent of the time), the OC will not be at the same location as the 'optical pole', which would line up with the MRP/PRP.

Laurie,

The OC doesn't change position when you introduce panto, just the principle axis. The only time the OC won't be aligned with the optical pole is when there is prescribed prism. In other words, when the OC is lowered to keep the principle axis aligned with the center of rotation of the eye, the lens is decentered vertically, just as it's decentered horizontally for PD.

So here's the confusion- if I use Martin's Rule to minimize on-axis errors (with the higher powers), am I upsetting the off-axis performance because the lens designer expects to see the design pole directly in front of the pupil, not aligned with the eyes center of rotation, with probably a default value panto tilt of about eight degrees? Or is the overall optimum position by the book- .5mm down per one degree of pantoscopic tilt?

One more question (if I haven't bent your ear too far already). Can you confirm that this lens is atoric (and I know that atoric is probably not the best description but you know what I mean) or is the ocular surface just aspheric to compensate for the flatter base curve? The latest info package from Shamir says the Auotgraph II SV is a "fully aspheric back-surface lens".

[Barry Santini]

Auto II SV is definitely atoric!

Barry

[Robert Martellaro]

Auto II SV is definitely atoric!

Barry,

Atoric it is, or as Harry would say, a non-rotationally symmetric aspherical surface with a variable P-value across both principle merdians.

It took a long time to find it (nothing at any of Shamir's websites) but find it I did, buried in the back of their US 2009 product catalog- "Shamir's EyePoint Technology develops a lens design with aspheric/atoric compensations".

In regards to tilt and face form, I wouldn't use too much of either if you fit the OC center pupil. Here's a worse case, tilt-wise, on a fairly common Rx at my shop. -8.00DS, 12 panto, 8 face... surface -7.35 -.48 x 57. So the lens is now half a diopter strong with a half cyl. And that's on-axis, not 15mm off-axis where a SV wearer isn't going to look anyway! Not too impressive for a high tech lens accurate to .01D.

[Laurie]

I just took the time to write a detailed reply, copied quotes from Barry, Robert, Harry, DRK, only to DELETE b/c I was typing too fast!

: (

Now my brain hurts.

Let me go pour a cup of tea and try again later.

...

brb!

[Laurie]

...

Ahh, I feel better now. ; )

OK, I will do my best to duplicate my deleted post...

Barry:

Find out what range of face-form (dihedral) values are also considered by Shamir to be acceptable? For instance, based on the range indicated for pantoscopic tilt, I'm thinkin' 0 to 8 degrees, yes?

Of course, Darling, anything for you:

Since the Auto II SV is not compensated for POW (Position of Wear), there are no defaults.

For the PAL Auto II series, if the As-Worn measurements are not given, the ray-tracing design software will default to the following:

Auto II Variable and Fixed PAL:
Faceform: 5 degrees
Pantoscopic: 9 degrees
Vertex Distance: 13mm

Auto II w/Attitude PAL (the wrap version):
Faceform: 20 degrees
Pantoscopic: 9 degrees
Vertex Distance: 13mm

I want to point out, that you are in a minute percentile on this...I ask wholesale labs all over the US, if they had to guess the percentage of ECP's actually giving POW measurements, the number has been very low, 1/2 percent at best. So, congrats on being an opti-frontier.

However, for the other 99.5 percent of opti's: PLEASE don't worry if you are not taking POW measurements yet! This method of measuring for PALs is in its infancy. Please do not shy away from this new technology just because you are not giving these additional measurements...the computer defaults will still yield a better product than they were wearing (assuming they were wearing a front surface molded product).

Robert said:

Barry,

Atoric it is, or as Harry would say, a non-rotationally symmetric aspherical surface with a variable P-value across both principle merdians.

Exactly!

And, Robert,

The OC doesn't change position when you introduce panto, just the principle axis. The only time the OC won't be aligned with the optical pole is when there is prescribed prism. In other words, when the OC is lowered to keep the principle axis aligned with the center of rotation of the eye, the lens is decentered vertically, just as it's decentered horizontally for PD.

You are correct. I meant to write the 'EFFECT' of the OC vertically, not the actual location itself. my bad! : )

Barry:

Auto II SV is definitely atoric!

correct again!

And, DRK: You are correct, it is not optimized for POW. It is a SV back surface aspheric/atoric, digitally surfaced product. Still better than a sphere or toric back surface, using traditional XY generator cuts.

: )

Laurie

[Barry Santini]

The main reason, I figure, for all the "WOW's I'm getting at deliver of Auto II SV for my astigmats over 0.75D Cyl is simply that:

Up till now, "best form" more or less left out optimization of cyl powers when processed with spherical base curves.

So...there's so much that is been, errr, wrong with sphero-cyl lenses for astigmats, that a window of opportunity is now open for easy improvement of the same.

If you want to imagine what is was like to see the type of improvement and experience the excitement of the original Punktal lenses, try these optimized FF SV lenses.

Guys and gals, it's really too easy: Get started with Auto II SV or Essilor 360 today.

You won't regret it. And your clients will think you're an optical maven.

Barry

[Barry Santini]

Hey, there's a loophole:

Shamir defaults to a VD of 13mm for wrap.

KB Co wrap solutions defaults to 11mm.

For powers above 4.00, this will yield a significant difference (0.25D) in the final sphere power ordered (and toleranced).

Beware!

Barry

[Chris Bowers]

Barry,

If you give us BVD, Wrap and panto we can applly on an Rx basis. The more info the better we can optomize these lenses.

Chris

[Barry Santini]

Barry,

If you give us BVD, Wrap and panto we can applly on an Rx basis. The more info the better we can optomize these lenses.

Chris

Chris, Thank you for calrifying this point.

What I meant to say was that ECPs who DO NOT supply POW parameters should be informed of what defaults the lens designers/labs use for making POW compensations, especially for wraps.

Barry