How to Measure Your Pupillary Distance (PD)
Average adult pd: 54-74 mm | average child pd: 43-58 mm
You’ll need to know your PD if you want to order glasses from All About Eyes with an outside prescription. If your glasses prescription doesn’t include your PD, we can show you how to measure it by yourself!
What is Pupillary Distance?
Pupillary Distance (PD) is the distance in millimeters between the center of one pupil to the center of the other. This measurement is used to determine where you look through the lens of your glasses and should be as accurate as possible.
Why is Pupillary Distance Important?
The PD helps determine the “optical center” of a prescription glasses lens. The optical center is where you look through the lens of your glasses and should be extremely accurate. If your PD is incorrect, it can cause eye strain, fatigue, headaches, and blurry vision.
How To Measure Your Pupillary Distance?
To measure your PD, you will need:
- 1 millimeter ruler
- 1 mirror
Station yourself 8 inches away from the mirror looking straight on.
With your head straight, place the ruler along your brow line.
Close your right eye and align the ruler’s zero over the center of your left pupil.
Then close your left eye and open your right eye.
With your right eye, read the mm line that lines up with the center of your pupil. This is your PD measurement.
You will need to measure your PD 3 to 4 times and take the average to ensure its accuracy.
This measurement process is for Single Vision and Progressive lenses. To have an accurate PD for Reading glasses, take the PD average and subtract 3.