What Is PD?
Your pupillary distance (PD) is the distance between the centers of your pupils, measured in millimeters. This measurement helps us position your lenses correctly in front of your eyes.
How to Measure Your PD
1. Get a millimeter ruler
Use a ruler that shows millimeters (mm).
2. Position yourself in front of a mirror
Stand comfortably in front of a mirror and look straight ahead.
3. Place the ruler over your eyes
Hold the ruler horizontally across your brow. Line up the 0 mm mark with the center of your right pupil.
4. Measure to your other pupil
Without moving the ruler, read the measurement at the center of your left pupil. That number is your single PD.
For example, if the center of your left pupil lines up with 62 mm, your PD is 62.
Single PD vs. Dual PD
A single PD is one measurement representing the total distance between your pupils, such as 62 mm.
A dual PD provides a separate measurement for each eye, such as 31 / 31 mm.
If your prescription already includes a PD, use the measurement provided by your eye-care professional.
Tips for an Accurate Measurement
Measure at least 2–3 times to make sure you get a consistent result. Keep your head straight, look directly ahead, and make sure the ruler stays level.
If possible, you can also have another person measure your PD while you look straight ahead.
Still unsure? Contact Yay Optics before placing your order and we'll be happy to help.