Your PD (pupillary distance) and how to measure it
Measure your pupil distance online using our online PD tool
*** The green box must precisely cover the magnetic strip ***
How to measure your pupil distance in a mirror or with a friend
About your pupillary distance
Your PD (pupillary distance) is the distance between the centre of your pupils, measured in millimetres. Your Optician will measure this during your sight test although it is unlikely to be written on your prescription. However, you can ask your optician for your pupil distance following your test. Your pupil distance measurement is important if you have a high prescription or require varifocal lenses but you can measure your pd online by downloading our pupillary distance ruler and using our instructions below. If you select 'Average PD' we will use an average pupil distance measurement based on the UK national average.
If you have trouble measuring your pupillary distance measurement you should download our printable pupillary distance ruler, take a photo of your self and email it to us. We can calculate your pupillary distance online and email you a confirmation once received. For lower prescriptions with distance or reading lenses you can select an average pupillary distance or measure your pupillary distance online for more accurate results.
Measuring your pupil distance measurement online is simple with our pd measurement tool. If necessary we can always measure your glasses PD from an old pair of glasses that you know are correct and we can use that pd measurement online for the pupillary distance between eyes.
Step 1 - Hold your head and credit card straight within the dotted circle
Step 2 - Ensure the green box exactly covers the magnetic strip on your credit card
Step 3 - Move the cross-hairs over the centre of each pupil
Note: Please double check that the green box exactly covers the magnetic strip otherwise the measurement will not be correct.
Your total pupil distance measurement should be between 55mm and 75mm.
We recommend measuring your pupil distance online using this simple tool. Feel free to email us if you need help or advice.