Pupillary distance, explained
Plain-English guides to measuring your PD and ordering glasses with confidence — no jargon, no hype.
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How to Measure Your Pupillary Distance (PD): A Complete Guide
Learn what pupillary distance (PD) is, why it matters for your glasses, and how to measure it accurately at home — with a ruler, a card, or your phone's camera. Includes common mistakes and how to check your result.
Read guide → How to Measure Your IPD for a VR Headset
Your IPD is the single setting that makes VR look sharp instead of blurry. Here's what it means, how to measure it with your camera, and the IPD ranges for the major headsets.
Read guide →VR Headset IPD Ranges: Which Headsets Fit Your Eyes?
A comparison table of IPD adjustment ranges for the major VR headsets — Quest 3, Quest 3S, Vision Pro, Valve Index, PSVR2, Pico 4 and more — plus what to do if your number sits near the edge.
Read guide →How to Measure Your Child's Pupillary Distance (PD)
Ordering glasses for your child online? Here's how to measure a child's pupillary distance at home, typical PD ranges by age, and when to rely on the eye doctor.
Read guide →Single PD vs Dual PD: What's the Difference and Which Do You Need?
Single PD and dual PD confuse most people ordering glasses. Here's a plain explanation of what each one means, when you need each, and how to convert between them.
Read guide →Near PD for Reading Glasses: What It Is and How to Calculate It
Reading glasses use a 'near PD' that's slightly smaller than your distance PD. Here's why, how to calculate it from your distance PD, and when it matters.
Read guide →What Is the Average Pupillary Distance? PD Ranges by Age and Gender
What's a normal pupillary distance? See typical PD ranges for adults and children, how PD differs between men and women, and how to tell whether your measurement is reasonable.
Read guide →Does Pupillary Distance Need to Be Exact?
How precise does your PD really need to be? Here's how much error is tolerable, why it depends on your prescription, and when a millimeter matters.
Read guide →Signs Your PD Might Be Wrong (and What to Do About It)
Eye strain, headaches, or blurry vision with new glasses can be a sign of an incorrect pupillary distance. Here's how to tell, and what to do next.
Read guide →What Happens If Your PD Is Wrong?
An incorrect pupillary distance can cause eye strain and headaches — but how much error actually matters depends on your prescription. Here's the real picture.
Read guide →Can You Get Your PD from an Old Pair of Glasses?
You can't read your PD off your glasses — but you can measure it using a pair you already own. Here's the marker method, and when it's reliable.
Read guide →Does PD Matter More for Progressive Lenses?
PD accuracy matters for every pair of glasses, but for progressives it matters a lot more. Here's why, and what to measure.
Read guide →Can You Order Glasses Without Your PD?
No PD on your prescription? Here's how to get your pupillary distance — measure it yourself, ask your optician, or find it on record — so you can order glasses online.
Read guide →How to Find Your PD for a Zenni Optical Order (No Eye Exam Required)
Zenni asks for your pupillary distance at checkout. Here's what that number means, where to find it, and how to measure it yourself if you don't have it.
Read guide →How to Find Your PD for a Warby Parker Order
Warby Parker asks you to submit your pupillary distance with your order. Here's what it is, where to find it, and how to measure it at home without a ruler.
Read guide →How to Find Your PD for a GlassesUSA Order
GlassesUSA needs your pupillary distance to make your lenses. Here's what PD means, where to find it, and how to measure it yourself at home.
Read guide →How to Find Your PD for an EyeBuyDirect Order
EyeBuyDirect needs your pupillary distance to make your glasses. Here's what PD means, where the number lives, and how to measure it at home.
Read guide →Do You Need Your PD for Sunglasses?
Does pupillary distance matter for sunglasses? It depends on whether they're prescription. Here's when you need your PD for sunglasses — and when you really don't.
Read guide →How to Read Your Eyeglass Prescription (OD, OS, SPH, CYL, PD)
Your eyeglass prescription looks like a code, but it's simple once you know the terms. Here's what OD, OS, SPH, CYL, Axis, ADD, and PD mean — and where to find your PD.
Read guide →Glasses and Eye Terms Glossary: PD, OD, OS, SPH, and More
A plain-English glossary of the eyewear and prescription terms you'll meet when ordering glasses online — PD, OD, OS, SPH, CYL, axis, ADD, and others.
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