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 → 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 →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.
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