Pupillary distance (PD) is the distance between your pupils, and it's used to ensure that your prescription is properly centered for the clearest and most accurate vision. The average adult’s PD is between 54-74 mm; kids' are between 43-58 mm.

We recommend getting your eyes examined by a professional to make sure you get the right PD measurement. But if for some reason you need to measure a PD yourself, follow the instructions below will help you get the most accurate results.

Step 1: Find a Ruler

Find a ruler with millimeter measurements and a mirror or a friend

Step 2: Find a Mirror

If using a mirror, stand eight inches away from the mirror.

Step 3: Rest the Ruler

Rest the ruler against your brow with your face straight. 

Close your right eye and line up the middle of your left pupil with the 0 line of the ruler.

Step 4: Measure the Distance

Measure across to the middle of your right pupil, still looking straight, and open your right eye. 

Read the mm line, this number is your PD, it should be between 46mm and 74mm.

If a friend help to take your measurements, 

keep both eyes open and have your friend put the zero on the millimeter ruler over the center of one pupil, 

then measure the distance to the center of the other pupil.

Step 5: Repeat the measurements

Repeat these steps 2 or 3 times to get an accurate and consistent number.