How to Measure Your Pupillary Distance (PD)

The pupillary distance (also PD, or écart pupillaire) is the distance in millimeters between the centers of your pupils. It ensures the optical centers of your lenses align with your eyes for sharp, comfortable vision. After adolescence, PD is generally stable, so you can reuse it for future orders. Our opticians store your PD securely in your Visionet file.

1 What exactly is Pupillary Distance?

PD can be a single number (total distance) or two numbers (half-PD right/left). Half-PD is preferred for accuracy—especially for progressive lenses or higher prescriptions.

Tip: Ask your optician to add your PD to your prescription. We’ll store it securely in your Visionet file.

2 Different ways to measure your PD

✔️ Ask your optician — they can provide your right/left half-PD.
✔️ Check past documents — invoices or job sheets sometimes include PD.
✔️ Request it at your eye exam — have PD written on the result.
✔️ Calibrated photo — take a straight, front-facing photo with a standard card (85.6 mm) under the nose.

Important: Remove glasses, look straight at the camera, keep head and card level.

3 How to take a good photo for PD measurement

Have someone take the photo at eye level, about 40 cm away.
Stand straight, look directly at the camera, and remove your glasses.
Hold a standard-size card straight under your nose (you can hide numbers).
Ensure both eyes and the card are sharp and fully visible.

✅ Correct example:

4 Sending your Pupillary Distance to Visionet

Upload your PD when placing your order or later from your account:

My Account → View order → My uploaded documents

Our opticians will validate and center your lenses precisely.

Why Pupillary Distance matters

Correct PD aligns lens optics with your visual axis. This prevents blur, reduces eyestrain/headaches, and is critical for progressive lenses and stronger prescriptions. Even a small error can noticeably impact comfort and clarity.

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FAQ – Pupillary Distance

Is PD the same as IPD (interpupillary distance)?

Yes — both refer to the distance between your pupils. “Half-PD” are the right/left values used for precision.

Single PD vs two numbers — which should I send?

If possible, provide right and left half-PD (e.g., 31.5 / 32.0 mm). If you only have a single PD (e.g., 63.5 mm), we can work with it, but half-PD is best for accuracy.

Typical adult PD ranges

Most adults fall between ~58–70 mm total PD. Children have smaller PDs and they change as they grow.

Can I measure my PD with a ruler at home?

You can, but it’s less reliable. We recommend a calibrated photo with a standard card or asking an optician to record half-PD values.

Is PD more critical for progressive lenses?

Yes. Progressive and high-power lenses are more sensitive to PD accuracy. Half-PDs are strongly recommended.

Can I reuse my PD for future orders?

Yes. After adolescence, PD is generally stable. We’ll save it in your Visionet file for next time.

Can I send you an old pair so you measure the PD from it?

Yes, you can. Please contact us first so we can send you the correct address and instructions. We’ll measure the PD from your old glasses and add it to your order.

What if my prescription doesn’t show PD?

No problem — ask your optician, send us a calibrated photo, or (after contacting us) send your old pair for measurement.