Lifetime Vision and Eye Care - PD means “pupillary distance,” which is the distance between the center of each pupil. This measurement is used to determine where you look through the lens
Why does my prescription not include the PD?
What your optometrist doesn't want you to know - The Boston Globe
The Pitfalls of Online Glasses: The Review | THE OPTICAL JEDI: A GUIDE TO THE MYSTERIES OF GLASSES
5 Ways to Measure Your Pupillary Distance (PD) at Home - Eyewear Genius
Why Do Opticians Measure Pupillary Distance?
How to Measure Your PD (Pupillary Distance) For Glasses At Home with GlassesOn App - YouTube
What is PD or Pupillary Distance | Safety Gear Pro