ABOUT
About Pupillary Distance
Pupillary Distance is an iPhone app. It uses the front-facing TrueDepth camera and AR face tracking to measure your pupillary distance — the millimeter gap between your pupils that you need to order eyeglasses online — and reports your far, near, and left/right monocular PD.
It can also suggest eyeglass frame styles for your face shape. It's free to try and ad-free.
Why we built it
Buying glasses online is easy until you're asked for your PD — a number most people don't have. We thought: every modern iPhone already ships with a TrueDepth camera precise enough to measure it. So we built a simple, private, on-device app around it.
About these guides
These guides are written by the same small team that builds Pupillary Distance Measure: PD, the iPhone app that measures pupillary distance with the TrueDepth camera. The byline on every post is the team, not a person: there is no individual author behind it.
What we can speak to first-hand is the measurement. We built the face-tracking pipeline that finds each pupil and converts a depth map into millimeters, and during development we checked its output against millimeter rulers and against pupillometer readings to see where the numbers agreed and where they drifted. That work is engineering, not clinical practice. No optometrist, optician, or other clinician is on our staff, and none reviews this site.
So for anything beyond the measurement itself, we work from published sources and cite them in the text: peer-reviewed research such as Jung and Chu (2024, Clinical Optometry) and McMahon (2012, Optometry and Vision Science), population data such as Dodgson's (2004) analysis of the ANSUR anthropometric survey, and patient guidance from the American Academy of Ophthalmology's EyeSmart. We re-read every guide at least twice a year, and sooner when a source is updated or the app changes.
None of this is medical advice, and no app measurement replaces an eye exam. For a prescription, vision that has changed, persistent eye strain or headaches, glasses for a child, or progressive and high-power lenses, see an optometrist or ophthalmologist.
Corrections
If we get something wrong, we fix the page and say so: corrected posts carry an updated date, and a substantive change — a number, a recommendation, a source we misread — is noted at the foot of the post with the date and what changed. Small edits such as typos, broken links, and wording are made without a note. Email contact@pupillarydistance.app with the page and the claim you're disputing, and we'll reply whether or not we end up changing it.
4.4★ · 310+ 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.