How to Measure Your Pupillary Distance
Pupillary distance is the space in-between the center of your two pupils measured in millimeters. Having the correct PD for your prescription ensures that your glasses are positioned so that your pupils look through the ideal spot on your lenses. You can get this measurement from your eye care professional or try it yourself.
1.Place a mm ruler directly under the center of your right or left pupil so that the ruler is horizontal. Stand in front of a mirror, or ask someone else to measure for you.

2.While looking straight ahead, measure the distance from the center of your left pupil to the center of your right pupil.

3.Repeat for accuracy.
Note that most people have a PD between 57 and 65mm, with an average of 62mm. For bifocal and free-form progressive lenses, two PD values are needed. In these cases, we recommend getting your PD directly from your eye care professional.