Your PD is the distance between your two pupils, expressed in millimeters. Sometimes the doctor will write two values (for each eye) or one value (for both eyes).
We need this measurement because it helps us to position the focus of your lens prescription in the right place for your frames. If your doctor did not include a PD measurement in your prescription, please feel free to use our simple guide (PDF) to take a measurement for yourself. You can also head to the nearest JINS, where our trained opticians will gladly take a measurement for you.