Some opticians have been known to charge a fee for this very basic measurement. If you can use a ruler, your'e already halfway there.

Pupillary distance (PD) is the length, in mm, between the centre of your pupils. This measurement determines where the centre of your lenses are, according to your eyes.

Via your biennial eye exam, your prescription doesn't always state your PD. On this occasion, the following steps will show you how to measure it yourself and why you certainly shouldn't be charged for it.


With help from somone else

Grab a friend and the nearest ruler.

Instruct them to carefully hold the ruler across your brow.

Using mm, your assistant can simply measure between your pupils.

Note your PD on your phone or write it on your prescription paper.


No help. Just me.

Stand about a foot away from a mirror.

Hold the ruler across your brow.

Close your right eye then align the ruler’s 0 mm with the center of your left pupil.

Look ahaead then close your left eye and open your right eye.

The mm line that lines up to the center of your right pupil is your PD.

Note your PD on your phone or write it on your prescription paper.


Using an App to measure my PD

Free : Link to free app

£0.99 : Link to paid app


Standard male and female PD sizes

Without your PD, opticians canuse average male/feamle PD sizes when fitting your prescription. It's always better to have your personal PD but these averages can be used as a general guide.

Male : 64mm

Female : 62mm

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