Your pupillary distance, measured in 10 seconds

Tap once. PDgo uses your iPhone's TrueDepth 3D camera to measure your PD automatically - total and per-eye, with a confidence rating. Ready to use when you order glasses online.

iOS app · iPhone X and newer (Face ID models) · iOS 16+ · Photos never leave your phone

PDgo iOS app home screen showing the Start Measurement button

Three steps. No ruler, no mirror, no helper.

Measuring PD by hand means a millimeter ruler, a mirror, and a lot of squinting. PDgo replaces all of it with the 3D sensor already in your iPhone.

1

Align your eyes

Hold your iPhone at arm's length and place both eyes inside the on-screen guide.

2

Hold still

PDgo captures three rounds automatically - about 10 seconds in total.

3

Get your result

Total PD, left-eye and right-eye PD, plus a confidence rating. Saved to your records.

Built for ordering glasses online

  • Total + per-eye PD - some retailers ask for dual PD; you'll have both.
  • Confidence rating - know when a reading is solid or worth re-taking.
  • Near PD reference - included alongside your result, for reading glasses.
  • Measurement history - keep your family's PDs on hand for the next order.
  • Private by design - everything is computed on your phone. No uploads, no account.
PDgo result screen showing total PD 63.0 mm with left and right eye values

Why the TrueDepth camera matters

A flat photo can't tell how far your face is from the camera, so photo-based PD tools have to guess using a credit card for scale. The TrueDepth sensor measures actual 3D distance - the same hardware that powers Face ID - so PDgo measures your pupils in real millimeters, not estimated ones. PDgo is a measurement reference for eyewear; for prescriptions and eye health, always see your optometrist.

Frequently asked questions

How accurate is PDgo?

PDgo uses the iPhone TrueDepth camera and captures three rounds automatically, then takes the median. Every result comes with a confidence rating so you know when a reading is reliable. It's intended as an eyewear reference, not a medical diagnosis.

Which iPhones are supported?

Any iPhone with Face ID (iPhone X and newer) on iOS 16 or later. The TrueDepth front camera is required for true 3D measurement.

Are my photos uploaded anywhere?

No. All processing happens on your device. Nothing is uploaded, and no account is needed.

Why do glasses retailers ask for my PD?

Your pupillary distance tells the lab where to place the optical center of each lens. If it's off, lenses can cause eye strain. Read more in What is PD?

Can I measure without the app?

Yes - you can use a millimeter ruler and a mirror, or our free online PD ruler. It's just slower and less precise than the TrueDepth method. See all three methods compared.

Ready to order glasses online?

Measure your PD once, use it every time you buy.

Download PDgo on the App Store