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A comment on Measuring Your Own Pupillary Distance.

Re:Measuring Your Own Pupillary Distance by Spare_account on Saturday September 02, 2017 @01:29PM (#15157185)
From the article:

I tried it out. Eight times. With eight different photographs. It measured me from a 61mm to 65mm PD. So call it accurate within ±4mm. How bad can that be?

I'm no mathematician but shouldn't that be ±2mm? And if so, then the following paragraph (where he says that glasses should be within 2mm to be usable) confirms that this method would suffice?

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Re:Measuring Your Own Pupillary Distance by phonon on Saturday September 02, 2017 @03:06PM (#15157661)
It's a mistake :-)

http://www.daniellivingston.com/2012/06/measuring-your-own-p...

AnonymousSeptember 12, 2013 at 1:02 PM It measured me from a 61mm to 65mm PD. So call it accurate within ±4mm.

Uh, no... This is ±2mm (around a center value of 63)

Daniel LivingstonSeptember 12, 2013 at 6:10 PM Oh yes that's true, I meant to explain it is inaccurate by up to 4mm.

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Re:Measuring Your Own Pupillary Distance by drdeadringer on Saturday September 02, 2017 @02:36PM (#15157502)
I tried doing it myself as well and came up higher than what my reality was by a couple mm as you describe. I ended up calling up my optometrist and provided my correct number no problem.
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Re:Measuring Your Own Pupillary Distance by nickez on Saturday September 02, 2017 @01:41PM (#15157252)
Also from the article, his actual PD is 69mm...
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Re:Measuring Your Own Pupillary Distance by Spare_account on Saturday September 02, 2017 @01:44PM (#15157267)
OK, I'll admit I didn't get that far.

But that means the method was accurate ±8mm?

Still not ±4mm...

(Unless I don't understand the ± notation)

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Re:Measuring Your Own Pupillary Distance by maxerickson on Saturday September 02, 2017 @02:29PM (#15157454)
1 face probably isn't enough to characterize the accuracy of the method.
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Re:Measuring Your Own Pupillary Distance by Spare_account on Monday September 04, 2017 @04:46AM (#15166698)
Well that kind of invalidates the entire article then! ;-)
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Re:Measuring Your Own Pupillary Distance by JustSomeNobody on Saturday September 02, 2017 @10:07PM (#15159321)
Depends on your Rx, but 4mm can be quite the headache at the end of the day each day.
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