how to measure pupillary distance


What is Pupillary Distance?

Your Pupillary Distance (also known as PD) is the space between the pupils of your eyes. This measurement ensures that your eyes match up with the optical center of your lenses. If not measured correctly, you can be prone to discomfort from your lenses, which is why it is important to measure your PD when it is not included with your eye prescription.

Note: The average adult’s PD measures somewhere between 54 to 74; kids are between 43 to 54.

How to Measure Your PD

It is very easy to measure your pupillary distance on your own. First, you will need a few things, such as a friend or mirror and a millimeter ruler.

You can download a printable pupillary distance ruler here and print it for your use (use a credit card to make sure it is scaled properly when printing).

If you have someone who can help you measure your pupillary distance, here is what you will need to do:

  1. Hold the millimeter ruler across your brow while your friend stands 8 inches (or 20 cm) away.
  2. Your friend will need to be sure that the ruler’s zero is centered to the right of your pupil.
  3. With the ruler straight, have your friend record the distance from the center of your left pupil.
  4. This distance is your PD.
  5. Ensure an accurate measurement by repeating 2 to 3 times.

If you do not have someone who can help you measure, you can also use a mirror, here is what you will need to do:

  1. Stand or sit 8 inches (or 20 cm) away from a mirror.
  2. Hold the millimeter ruler above your eyes and flat against your brow.
  3. To measure your right eye, close your left eye and note the mm mark on the ruler directly above the center of the right pupil.
  4. This distance is your PD.
  5. To ensure an accurate measurement, repeat 2 to 3 times.

It is always best to obtain your PD measurement from your ophthalmologist to ensure that it is accurate.