What is Pupillary Distance?
How to Measure Your Pupillary Distance
- Stand 8 in. away from a mirror.
- Hold a ruler against your brow.
- Close your right eye then align the ruler’s 0 mm with the center of your left pupil.
- Look straight then close your left eye and open your right eye.
- The mm line that lines up to the center of your right pupil is your PD.
PD = 62 mm
The average adult’s PD is between 54-74 mm; kids' are between 43-58 mm.
Why Is It Important?
Every set of prescription lenses has an “optical center,” which is determined by pupillary distance. Pupillary distance is used to determine where you look through the lens of your glasses and should be as accurate as possible.
Measure The Distance
Your prescription may tell you your PD. But if the PD is not available, use your friend or a mirror to help you figure it out.
MEASURING YOUR OWN PD
Stand 8 in. away from the mirror
With your face straight, hold the ruler against your brow
Close your right eye and align the ruler’s zero to the center of your left pupil
While looking straight, close your left eye and open your right eye
Read the mm line that lines up with the center of your right pupil. This number is your PD
A Few Things to Note
Measure your PD 3-4 times to ensure it's accurate and consistent.
Range of Adult PD: 54-74 mm
Range of Child PD: 43-54 mm