Blocking a PAL with prism in manual mode on ICE 1000

It's Friday and I'm not thinking straight.

I'm blocking a polarized PAL on an ICE 1000 blocker. The Rx in the horizontal meridian is -4.50 OU and the horizontal prism is 3.00 BO OU. The frame PD is 77 and the patient's PD is 60 (blocking with 8.5 mm in OU). It's a lot of decentration and I'm pretty confident the PD will come out wrong once edged if I just enter 60. I'm sure the same thing would happen if I blocked it using a CE9 manual blocker.

I know how to offset the lens position while blocking a clear lens with this device using automatic lens dot detection with PAL markings, but it doesn't work like that for polarized lenses on the ICE 1000.

Is there a way to calculate an adjusted PD to enter into the blocker using Prentice's rule so it comes out right?

No calculations necessary in ICE1000. Dot up the lens and orient it yourself in manual mode. Prism will have no effect because it's not even detecting the lens in manual mode. And as long as the lab did the prism right everything will be correct. You're overthinking it, block it up manually the same as you would without prism.

Agreed. I blocked every progressive I ever did on the ice1000 in manual mode. No need to adjust anything for prism.

I have to disagree. I always dot the lens and have the ICE 1000 find the dots and leave the lens centered for a typical PAL. If you use manual mode with a bit of decentration due to frame PD being different than patient PD, or have a lens with a bit of prism, the PD will come out either wider or narrower if you re-check the PD after it's edged. The easy way to tell is if you put a PAL with horizontal prism on the blocker, the image of the lensmeter sensor shifts (as it should). I've figured out the way to compensate for this with a clear PAL with prism but it won't find lens dots on a polarized lens.

Put it in "passive" and "manual". Align the FF engravings (or neutralize and spot SV lenses with prism) with the marks and Bob's your uncle.

Attachment 15139

Like I said, this is how I have blocked every progressive lens in the ice-1000 for about 11 years. There is nothing else to it.

Quote:

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Originally Posted by DanLiv

No calculations necessary in ICE1000. Dot up the lens and orient it yourself in manual mode. Prism will have no effect because it's not even detecting the lens in manual mode. And as long as the lab did the prism right everything will be correct. You're overthinking it, block it up manually the same as you would without prism.

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This is also how I have done all of my progressive lenses as well.

Perhaps you are thinking about compensating for the prism that the lab put into the progressive? Attachment 15140