What is Pupillary Distance (PD)?
Pupillary distance (PD) is the distance between the centers of your pupils, measured in millimeters (mm). A correct PD measurement helps align the optical center of your lenses for clearer, more comfortable vision.
Why It Matters
Accurate PD distance improves lens centering and helps reduce visual discomfort.
Single vs. Dual PD
Some orders use one number, others use two (OD/OS) for right and left eye.
Printable PD Ruler
Print this page at 100% / Actual size on A4 paper or US letter paper. For the most accurate results, measure 2–3 times and use the average.
How to Measure Your PD at Home
The average adult PD is usually between about 54 mm and 78 mm. For the most accurate result, measure 2–3 times and use the average.
Single vs. Dual PD (OD/OS)
Use single PD when checkout shows one PD field. Use dual PD when checkout asks for two PD fields (right/left).
| Type | What It Looks Like | When To Use |
|---|---|---|
| Single PD | One number (e.g., 63mm) | When checkout shows one PD field |
| Dual PD | Two numbers (e.g., OD 31mm / OS 32mm) | When checkout asks for two PD fields (right/left) |
Can You Measure PD Online?
Yes. Online tools can help you estimate your pupillary distance. For the best accuracy, especially with a stronger prescription, consider getting PD measured by an eye care professional.
Option 1
Use a photo tool (phone or webcam)
Use a standard card for scale. Keep your face centered, look straight ahead, and use good lighting.
Option 2
Use a printable PD ruler (recommended)
Print at 100% / actual size, then follow the step-by-step guide above for a more reliable PD distance.
Option 3
Ask a friend to measure for you
A helper can improve accuracy because you can keep both eyes open and your head steady.