Pupillary Distance (PD)
How to Measure Your Pupillary Distance (PD)
The Pupillary Distance, or “PD,” measures the distance between your pupils in millimeters. This guarantees the optical center of your prescription lenses is in the correct spot.
Your prescription may have your PD already listed. If not, use your friend or a mirror to help you take the measurement.
When you wish to measure this yourself, the guide below will arm you with simple, step-by-step instructions to measure your PD at home. Don't worry if you do not have a metric ruler, we can convert a measurement from inches to millimeters for you, but please try to measure accurately down to 1/32".
In the example image above, the PD measured 59. Here is how that was determined:
- Stand approximately 10 inches from the mirror.
- Holding your head straight and still, place the millimeter ruler against your brow.
- With your right eye closed, line up the ZERO mark with your left pupil.
- With the ruler on your brow, next close only your left eye and read where your right pupil lines up.
- This is your PD.
Measure 3-4 times for accuracy and simply use the average. A typical range for children is 43-53, and for adults it is 54-74.