Person measuring their pupillary distance with the iPhone front camera

Know your PD
before you buy glasses.

The pupillary distance app for iPhone. Measure your PD with the front camera — accurate to the millimeter — then order glasses online with confidence. Free to try, ad-free.

Download the App

4.5★

App Store rating

languages supported

100%

on-device — nothing uploaded

FEATURES

Everything you need before you order glasses.

Front-camera PD

Your iPhone's TrueDepth camera maps your face in 3D and measures the distance between your pupils — no ruler, no mirror, no optician visit.

Far and near PD

Get your distance PD for everyday glasses and your near PD for reading, plus separate left and right monocular values.

Frame finder

Answer three quick questions about your face shape and get eyeglass frame styles that actually suit you.

HOW IT WORKS

Person holding an iPhone at arm's length to measure pupillary distance with the front camera

Hold your iPhone at arm's length and Pupillary Distance maps your face with the front camera. Your PD appears in seconds — no ruler, no guesswork.

A live reading shows your pupillary distance in millimeters as the camera locks onto the center of both pupils.

Pupillary Distance app showing a live PD reading in millimeters on an iPhone

Get both numbers opticians ask for: your far PD for distance glasses and your near PD for reading.

App showing far PD and near PD values for ordering glasses online

See left and right monocular PD too, so prescriptions that list each eye separately are fully covered.

App showing separate left and right monocular pupillary distance values

TESTIMONIAL

"I ordered glasses online for years guessing my PD. One scan and I finally had the exact number — my new lenses actually line up with my eyes now."

Lena Hoffmann

Ordered glasses online
"Tried a few PD apps and this is the only one that gave me the same reading every time. Far and near PD in under a minute, no ruler taped to my face."

Marcus Webb

Glasses wearer
"The optician wanted to charge me just to read my PD off my own face. This measured it at home for free — and the frame suggestions were spot on."

Daniel Reyes

Bought glasses online

FREQUENTLY ASKED QUESTIONS

What is pupillary distance (PD)?

Pupillary distance is the distance in millimeters between the centers of your two pupils. Opticians use it to center each lens in front of your eyes, which is why you need it to order glasses online.

How does the app measure my PD?

Pupillary Distance uses the iPhone's front camera and TrueDepth AR to map your face in 3D and measure the distance between your pupils — no ruler, mirror, or optician visit required.

How accurate is measuring PD with an iPhone?

On a modern iPhone the front-camera depth sensor measures PD to within about a millimeter — the same tolerance opticians work to. For a strong prescription, take two or three readings and use the average.

Which iPhones does the app work on?

Any iPhone running iOS 16 or later. iPhones with a TrueDepth (Face ID) camera give the most precise depth-based reading.

Is my PD private?

Yes. Every measurement is stored locally on your device. There is no account and no server — nothing about your face or your PD is ever uploaded.

What's the difference between far PD and near PD?

Far PD is for glasses you look through at a distance; near PD is slightly smaller and used for reading glasses, because your eyes converge when you focus up close. The app gives you both, plus left and right monocular PD.

BLOG

Measuring pupillary distance at home with a millimeter ruler and an iPhone front camera

How to Measure Your Pupillary Distance (PD) at Home

Three reliable ways to measure your pupillary distance at home — with a ruler and a mirror, with a friend, or with your iPhone — plus how to get far, near, and monocular PD right.

4.5

135+ Reviews

Your PD, measured
in under a minute.

Pupillary Distance turns your iPhone into an accurate PD meter. Measure once, then order glasses online with confidence.