The PD/Pupillary Distance is the distance between your pupils, it ensures the correct centration of your Prescription lenses in front of your eyes.
The most common method used to measure the PD involves a simple millimetre ruler. Normally the Optician holds the ruler between thumb and forefinger and steadies his hand by placing his remaining three fingers against the patient's head. The Optician then closes his right eye. The patient is instructed to look at the opticians open left eye while the optician lines up the zero mark on the ruler with the edge of the iris in the patients right eye. The optician then closes his left eye and opens his right eye and instructs the patient to look at the open right eye. The PD is then measured at the edge of the Iris in the patients left eye.
Getting Your PD
These our recommendations for getting your PD measurement...
From your optician - You can request this information from your optician after your eyetest or you can contact them for this measurement if your eye test was done in the past.
Measure PD with a Mono PD ruler - You can measure your pupillary distance (PD) yourself with a PD measure ruler. Simply follow the video above for further instructions.
Normally the Optician holds the ruler between thumb and forefinger and steadies his hand by placing his remaining three fingers against the patient's head. The Optician then closes his right eye. The patient is instructed to look at the opticians open left eye while the optician lines up the millimetre mark on the ruler with the centre of the patients right eye (Pupil). The optician then closes his left eye and opens his right eye and instructs the patient to look at the open right eye. The optician lines up the millimetre mark on the ruler with the centre of the patients left eye (Pupil). Add these two numbers together to obtain your PD/Pupillary Distance, for example if you had RE; 32mm and LE; 33mm you would enter a PD/Pupillary Distance of 65mm, On average the PD in an adult is usually between 60 and 66 millimetres. You can also add a note in the additional info box when ordering to list your mono PD measurements if you wish, this will be useful if ordering Varifocals/Progressive lenses.
Measure Your PD via an App - If you would like an accurate PD measurement and have an appropriate mobile device, we can highly recommend the GlassesOn app available from the Apple App Store or Play Store. See our guide to using this app below:-
Send glasses for PD check - If you have a spare pair of glasses that are in good condition with both lenses still in the frame you can choose to send these with your order when entering your prescription values by selecting the 'Send glasses for PD check' option (there is a £5 service charge of this service including return postage of your glasses). Once you have placed your order, please send them to us together with a print out of your order, we will record the pupillary distance measurement from these to ensure accurate centration of your lenses.
Average PD - On average the PD in an adult is usually between 60 and 66 millimetres. (see diagram). If you are unsure of your PD you can select the Use Average option (63mm), however we would always recommend an accurate measurement if possible especially for higher prescriptions or where multifocal lenses are required.