What is Pupillary Distance (PD)?
|Pupillary distance (PD) is the measurement (in millimeters) of the distance between the pupils of your eyes.
Why is my PD measurement needed?
Pupillary distance is an important measurement used to determine the proper lens shape and alignment of your prescription correction to your line of vision. Without an accurate PD measurement, correcting vision can be difficult since lenses need to be aligned over the center of your pupil for proper clarity.
Where is my PD measurement on my prescription?
Your PD measurement is typically written beneath the prescription, as in the example below:
How do I read my PD measurement on my prescription?
Generally, adults have a PD within the range of 54-68 mm, while children have a PD within the range of 41-55 mm. Pupil distance can be measured in two ways. The first is called binocular, which is a pupil-to-pupil measurement, this type of measurement will be between 41-80 mm. The other type of measurement is called monocular, which is a per-eye measurement from the pupil to the middle of the face, this type of measurement will be between 20-40 mm. Monocular measurements are most often used when the face is not perfectly symmetrical, meaning one eye is closer or farther from the middle of the face than the other.
PD can be written on your prescription in a couple different ways. Below is a chart with some of the most common ways PD is written, along with how to enter the measurement when creating and purchasing glasses from our site.
What if my PD isn't on my prescription?
PD is typically measured by your eye doctor during your eye exam. If your eyecare provider does not measure your PD during your eye exam, or if the PD is missing from your prescription, you can request a PD measurement. Some eyecare providers may charge an extra fee for a PD measurement, but many will include it as part of the eye exam. If your prescription does not have your PD measurement on it then you can measure your PD yourself by reading the "How do I measure my own PD" section.
How do I measure my own PD?
Follow the instructions below to measure your own PD at home.