Pupillary Distance

What Is Pupillary Distance?

Here at Oscar Wylee, we are dedicated to providing you with the best eye care and products. When it comes to making your glasses, it is important for us to know your pupillary distance (PD) measurement to make sure that the lenses are placed correctly over your eyes, allowing you to have clear and comfortable vision. 

What is pupillary distance (PD)?

Pupillary distance is measured in millimetres and records the distance between the middle of each of your pupils. This measurement is used to ensure the lenses of your prescription glasses are positioned correctly to give you the best possible vision. PD measurements are important for people who wear glasses and will always be taken before you purchase prescription eyewear.


If you are unsure about your PD measurement or want it professionally measured, visit an Oscar Wylee Canada store near you and our friendly staff will assist you.

Due for an eye exam?

We recommend that everyone should have an eye exam with an optometrist at least once every 2 years.

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Binocular vs monocular pupillary distance

There are two kinds of pupillary distance measurements. One measures the total distance between your pupils and the other consists of two measurements which are between the centre of each pupil to the bridge of your nose.

Binocular PD

As explained above, binocular PD is the total measurement between the pupils. 

Monocular PD

Because not everyone’s eyes are equally proportioned, we might need to take two PD measurements, as one pupil could be a couple of millimetres further away from the nose bridge than the other.


Pupillary distance is written Right Eye first and Left Eye second: 30/32.

What is the average pupillary distance (PD)?

While not everyone’s PD is the same, there is usually a common range in which they fall into.

  • Adult average: 63mm
  • Female average: 62mm
  • Male average: 64mm
  • Child average: 56mm

Why does PD matter?

We need to know the distance between your pupils in order to custom make your glasses for your face. With your pupil distance measurement, we can make sure the optical centre of the lens, which holds the clearest vision, sits directly in front of your pupil.

How do I find my PD for glasses?

We recommend you have your PD measured in-store by our trained optician. It will most likely be done when you are being fitted for your new glasses using a pupillometer also known as a PD metre.

How to measure pupillary distance for reading glasses

When your PD is measured for prescription reading glasses, you will need your Near PD, which is calculated as 3-4 mm less than your Distance PD.


For example:


Distance PD: 63mm, Near PD: 63 – 3= 60mm

Pupillary Distance

What happens if my pupillary distance is off?

It is crucial to have your correct PD measurement – an incorrect PD can make it feel like you are wearing a different person’s glasses. 


If your PD is incorrect, it can cause headaches, blurry vision and eye strain.


That is why we recommend you visit us in person to have your PD measured by a professional.

Does my PD change over time?

Your pupillary distance is expected to change as you grow from a young child into an adult, as your skull shape changes and gets bigger. But once you reach adulthood, it is unlikely that your PD will change.

Is my PD listed on my prescription?

No. In most cases, you will have your pupil distance taken after your eye exam and once you’ve picked out your glasses. An optician will measure your PD using a PD metre, and add the measurement to your order which will be available for reference the next time you purchase glasses.

I’ve got my PD. What happens next?

Once your PD has been measured, you can move on to purchasing your prescription glasses.

Visit us in-store

Come in to one of our Oscar Wylee Canada stores and our friendly staff will assist you in all your glasses and optometry needs.

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