P.D. is short for Pupillary Distance. This is simply the distance, in millimeters, between your two eyes.
We need it to make your new eyeglasses so that you’re able to see clearly. It helps us to line up the optical center of the lenses to the center of your pupil, ensuring the best possible vision.
You can obtain your PD a number of ways: 1) ask your eye doctor for it at your examination; 2) go into a local optical shop and ask for it to be measured; or 3) measure it yourself using our Printable PD Ruler at the footer of the page.
The average PD for an adult ranges between roughly 55 and 68 millimeters, although you may be slightly out of this range on either end. If you obtain a measurement that is far off (e.g. 45) you will want to measure again.