How to Find Your PD for an EyeBuyDirect Order

To order prescription glasses from EyeBuyDirect, you'll need your pupillary distance. If your prescription didn't come with it — which happens a lot — here's what the number is and how to get it without a trip back to the optician.

What PD is

Pupillary distance is the distance, in millimeters, between the centers of your pupils. Also called interpupillary distance, it tells the lab where to place the optical center of each lens so it lines up with your line of sight. A correct PD is what lets a correct prescription actually feel right on your face.

EyeBuyDirect uses two formats:

• Single PD — one number, the distance from the center of one pupil to the other.
• Dual PD — two numbers, each measuring from a pupil to the middle of the nose, with the right eye listed first.

A common mix-up

The numbers printed on the inside of your current frame's arms are not your PD. Those describe the frame itself — lens width, bridge, arm length. Your personal pupillary distance isn't etched anywhere on your glasses, so if you're hoping to read it off an old pair, that's the wrong place to look.

Where to find it

1. Your prescription. PD is sometimes listed, sometimes not. Check first.
2. Ask your eye doctor. If it's missing, the office can usually provide it.
3. EyeBuyDirect's own tools. When entering your prescription on their site, pressing the "i" button in the PD section opens a tool that can measure it with your phone's camera. They also offer a printable millimeter ruler and a mirror-based method — stand about 8 inches (20cm) from a mirror, hold the ruler horizontally against your brow, and read across from pupil to pupil.
4. Measure it yourself another way. Any reliable at-home method works.

Skip the ruler

If the ruler-and-mirror dance feels fiddly, our PD measurement tool uses your device's camera with the iris as a built-in scale — no printout, no card, no download. It returns both the single and dual numbers, ready to enter into EyeBuyDirect's PD fields.

Worth remembering

At-home measurement is an estimate, not a clinical reading — the same is true of every retailer's camera tool. For low-to-moderate single-vision prescriptions that's usually fine. For progressives or strong prescriptions, measure a few times and, if you can, confirm against a professional measurement. Consistency across a few tries is your best signal that you've got it right.

Sources

• EyeBuyDirect — How to Measure Pupillary Distance (PD)
• EyeBuyDirect — Pupillary Distance Ruler (Printable PDF guide)
• EyeBuyDirect — How to Place an Order for Rx Glasses Online