How to Measure Your Pupillary Distance (PD) at Home
Your PD centers each lens in front of your pupil. If your prescription doesn't include it, you can measure it at home in a couple of minutes.
What you need
A ruler with millimeters and a mirror, or a friend to help.
With a mirror
- Stand about 8 inches (20 cm) from the mirror.
- Hold the ruler flat against your eyebrows.
- Close your right eye and line up the 0 with the center of your left pupil.
- Close your left eye, open the right one and read the number at the center of your right pupil.
- Repeat two or three times and use the average.
With a friend
Look straight at a point far away while your friend holds the ruler and measures from the center of one pupil to the other. Looking far keeps your eyes parallel.
Typical values
Most adults have a PD between 54 and 74 mm. Children usually measure between 43 and 58 mm.
Frequently asked questions
What is dual PD?
Two numbers, one for each eye measured from the center of the nose (for example 31.5 / 32). It is more precise, especially for progressives.
What if I am off by 1 mm?
A small difference is usually fine for single-vision lenses. For strong prescriptions or progressives, precision matters more.
Related guides
This guide is for information only and does not replace an eye exam. If you have eye pain, sudden vision loss or flashes of light, see a doctor right away.