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Measuring your Pupillary Distance (PD)

Your Pupillary Distance (PD) is the distance between the centres of your pupils, measured in millimetres.

This measurement is an important piece of information, as it determines where you look through the lenses of your glasses. To deliver the very best vision in your new glasses this measurement needs to be as accurate as possible.

Your PD is usually written as one value (e.g. 70mm) but sometimes written as 35/35 if you are symmetrical or 34/36 if one eye is slightly further away from the centre of the nose than the other, which is very common.

The average PD measurements for women is 62mm and for men 64mm. Between 58 and 68 is quite normal though.

Sometimes, your optician will give you your PD or include it on your prescription. However, your PD measurement doesn't change between prescriptions, so any prescription glasses you have available will be fine to send to us and our specialists will be able to take the measurement from them.

Otherwise, please follow the steps below which will help you measure it for yourself.

You can measure your PD in one of two ways:

Method A: Use any card that utilises a magnetic strip (credit/debit card, library card, etc)

We have computer software which can measure your PD from a photo - hold up any card with a magnetic strip (we use this for scale), e.g. library card, credit/debit card, and position the card beneath your nose as per the diagram below.

Then email the picture to us (at along with your order number from your order confirmation email) and we will work out your PD.


Method B: Use a ruler and a mirror/friend

Stand 8 in (20cm) away from a mirror or a friend. Place and hold the ruler against your brow. Keep your face straight

Close your right eye and align the rulers zero to the centre of your left pupil.

Try not to move your head or the ruler. First open your right eye and close your left eye. Look straight ahead and read the millimetre line that matches up with the centre of your right pupil. This number represents your single PD in millimetres.