What is my Pupillary Distance (PD)?
Your papillary distance (PD) is the distance between the centre of one pupil to
the centre of the other pupil while your vision is fixed on a distant target. The
industry standard is to have this measurement expressed in millimeters.
This measurement is important in the making of your prescription spectacle as it
ensures that the optical centres of your spectacles lenses are aligned to your pupil
positions.
Positioning lenses correctly in relation to the centre of the pupils is especially
important for higher powered lenses (above 2 diopters).
Your PD will be measured by your eyecare practitioner at the time of your eye test.
If your spectacle prescription does not include your PD measurement you can:
- Call your eyecare practitioner and request it (this is our preferred
procedure)
- or You can measure your own PD using one of the following methods
Measuring Your Own Pupillary Distance (PD)
- Stand one meter (approximately) away from a mirror.
- With or without your spectacles on, close your right eye and centre
the zero millimetre marker of a ruler at the centre of your left eye.
- To ensure the ruler is stable during the measurement, rest the ruler
on the bridge of your nose during this procedure.
- Now, holding the ruler steady, open your right eye and close our
left eye.
- Using your finger or thumb, mark the ruler where your right eye pupil
centre is located.
- The millimetre mark of your thumb placement is your PD measurement.
- Complete this procedure three or more times to ensure consistency
of your measurement.