rbmrtn
Thinks s/he gets paid by the post
So if your self measurement of PD is off a bit, what does that do in relation to the performance of your eye glasses? Right now all I do is just keep the readers at the bottom of my nose when reading as I only need them for reading. Of I could add a 3 inch extension to my arm, I could pitch the glasses and be fine.
It's more important for higher power prescriptions. Also it really isn't part the prescription, the doc usually doesn't measure. Most of the time when you get the paper from the doc, the PD is blank. The optician measures the PD as it is part of how the lens is positioned in the frame.
This site has a tool to upload a pic and calculate the PD Free Pupillary Distance Test Online | Free PD Self Test by FinestGlasses.com