PDExact: PD Measure

Ordering glasses online and the form asks for your PD? PDExact measures your pupillary distance from a photo, using any bank or credit card as the ruler.

Take a selfie with the front camera (or pick a photo) while holding a standard card flat against your forehead. Then place the handles: the two ends of the card, the centre of each pupil, and your nose bridge. PDExact converts pixels to millimeters from the card's known 85.60 mm length and shows your PD and both mono PDs live.

• PHOTO + CARD SCALE — the standard ID-1 card size (a bank or credit card) sets the scale right in the photo, so no screen calibration is needed.
• AUTO-PLACED PUPILS — on-device face detection pre-places the pupil and nose-bridge handles when it can; you can always drag them.
• MAGNIFIER — hold any handle to see a zoomed view with a crosshair for precise placement.
• REAL MONO PD — right and left mono PD are measured from your nose bridge to each pupil, not just half of the total.
• RESULT PDF — a one-page PDF with your PD, both mono values, the date and the disclaimer, ready to share or save to Files, in the app's language.

For the best reading, keep the card flat against your forehead, face the camera straight on and hold your head level.

Not a medical device: PDExact is a shopping aid only. It does not diagnose conditions, replace an eye exam, or provide a prescription. For clinical PD or medical advice, see an eye care professional.

Everything stays on your iPhone. Nothing is uploaded and no account is needed.

Measuring is free; saving a result PDF includes 3 free exports. A one-time $4.99 purchase unlocks unlimited result PDFs. No subscription, no ads.

Questions: overlapmarr@gmail.com