# Optical Forums > General Optics and Eyecare Discussion Forum >  Zeiss i.Scription

## john-atlanta

Does anyone have any experience with this device, which looks similar to the Visionix and the Opthonix machine?  

Anyone know when and if it will be in the USA and at what cost?

Also, any comments on the iTerminal or CyberEyes dispensary devices?

John

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## xiaowei

> Does anyone have any experience with this device, which looks similar to the Visionix and the Opthonix machine? 
> 
> Anyone know when and if it will be in the USA and at what cost?
> 
> Also, any comments on the iTerminal or CyberEyes dispensary devices?
> 
> John


Hi John,

just to put terms clear: *i.Scription* is the way to calculate an optimized refraction from the low and high order Zernikes and make glasses that are outside of 0.25 or even 0.12D steps. ("Inscribing" the individual aberrations on the glasses, an analogy IMHO not very appropriate and too much similar to what Ophthonix claim(s/ed) and what I already critized in another thread.) 

*i.Profiler* is the machine to measure the aberration pattern you are probably referring to.

Here is a probably interesting paper from Zeiss, unfortunatelly in German only.:(

http://www.doz-verlag.de/doz_archiv/...bf6c0de8d013e2

BUT it does NOT really explain the rationale behind the system. The title of the last chapter reads "Do the glasses correct higher order aberrations of the eye" and the text definitely says: NO. How the higher orders really enter is IMHO not explained to a satisfactory extend. If you start with Zernikes, it is the special feature of the Zernikes that they are orthogonal over the pupil, i.e. compensating the lowest order (by cylinder) automatically also guarantues best possible "cancellation" for higher orders at least with respect to RMS error. 

The paper cites another paper by Chen et. al. that seems to proove that the impact of different aberration orders on the visual acuity is more complicated, but the examples given are only for a certain orientation of the "Snellen-E"s and I don´t really buy especially the 5th order pentafoil in Fig. 3 from own calculations of the impact of different Zernikes on image quality.

Also the paper does not answer and even address the obvious question: If some "unsual" combination of low order sphere and cylinder can optimally compensate higher orders, why is it not found by regular subjective refraction?

Hope this helps

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## john-atlanta

Superb post! 

One wonders what a company like Zeiss is doing with an instrument and lens "optimization" strategy that sounds so much like the iZon.

Really, my main interest in instruments like this is to drastically reduce my time spent saying "which is better, one or two".  I don't give a rats a$$ about these optimized lenses (yet).  I really just want to get an autorefractor that actually works!

It begs the question, which instrument allows one to most quickly and accurately determine the refractive status of patients that can be used to make regular lenses?  Is it ophthonix, visionix, zeiss, marco/nidek or the tracy tech itrace?


Ophthonix is certainly winning the race on price with the new price structure of their instrument.

Someone please rescue me from subjective cylinder chasing!!!  ;)

John

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## allanon

We ordered a CyberEyes a couple weeks ago at the IDOC meeting in New York.  One of my employees is married to ther Zeiss rep, so I have had plenty of time on the iTerminal.  The main deterrant to the Zeiss version of digital dispensing is the stupid gadget you stick on the frame.

The clincher for CyberEyes for us is the web integration.  Sold.  If you're in Atlanta, you just run up to Raleigh for training.  Our dispensing tables are being remade as part of an office update, so we are delaying deploying CyberEyes until the first week in May.

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## Bobie

I would like to hear comment of wears who try i.Scription and iZon in the same time.

:cheers:

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