The PDCheck will provide you with the following pupillary distance (PD) measurements:
Distance PD: This is also known as Dual PD, it is the combined value of the distance from the center of your left pupil to the center of your right pupil. This is the most commonly requested value by most manufacturers of glasses.
Single PD (Left and Right): These values are the distance from one pupil (either the left or right) to the center of your face. You can either use this value or your distance PD when ordering glasses. We suggest you use the single PD values if there is a large gap between your right and left PD.
Near PD: This is the PD value that you need when ordering a pair of bifocal or progressive lenses.