#1 Top Ranked App for measuring Pupillary Distance also known as PD. PD Meter App by GlassifyMe is the perfect tool to measure your Pupillary Distance (PD) quickly and accurately. Simply take a picture holding a standard sized card with the magnetic strip facing the camera and let us do the rest. Note: Using a credit card is NOT required, nor recommended. Please use a points or rewards card. The card is only used for the purpose of reference sizing. What is PD? PD, short for Pupillary Distance, is the distance between the center of your pupils in millimeters. This measurement is important during the manufacturing of your prescription glasses to ensure you get proper vision. This measurement is also needed for your VR (Virtual Reality) headsets. Why PD Meter App? • Measure your Distance and Reading PD in 3 quick steps • Automatically detects your eyes and pupils • Advanced algorithm that calculates and gives precise results • Take a selfie, ask a friend to take your picture, or import photo from gallery. ** Watch the full video tutorial at https://youtu.be/eIuSNoEZWig