Questionable Specsavers measurement of pd

Ash_Pole

A few years ago I bought some glasses from one of the online places. I measured my pd (pupillary distance) using the ruler/phone method and got 65mm.

This time around I thought I'd get the experts to do it so used Specsavers. The technician there measured it as 68mm - quite a difference. She did this by hanging some contraption from the empty frames I was wearing and taking a photo, then using thier fancy software on the ipad.

I questioned her measurement and she got someone else to check. This guy asked me to hold a ruler thing against my forehead and look straight ahead, chatted briefly to the first techy and then moved on (the shop was pretty busy). She said he confirmed the measurement. I shrugged and ordered the glasses.

But now I'm home I tried measuring it again myself, both in a mirror and direct from the camera (at a distance of maybe a foot). I'm still getting 65mm.

TLDR - how likely is it that the Specsavers measurement was inaccurate?

theoretica

They could both be right - the way you describe measuring it in a mirror or by camera your eyes are likely to be focussing on something close up - so pointing inwards. Specsavers may have been measuring you for distance vision. 3mm is about average for the difference between PD for near and for far distance.

suki1964

I just had mine measured ( last week ) and the technician I saw ( and have seen for the past 12 years) refuses to use the iPad contraption and prefers to measure using the ruler

When I asked her why, she says the iPad is always out and she doesn't trust it where as she has been fully trained on measuring. She done a trial on me and yet there was a 3mm discrepancy . Now as I say she has always measured me for glasses and Ive never once had a problem