How to Measure Your Pupillary Distance

Your optician is required to include your pupillary distance on your prescription. Look for the abbreviation PD, EP, or DP on your document.

You can also find this value on a previous invoice from your optician or by contacting your ophthalmologist directly.

This is the most reliable method — use it whenever your prescription is available.

All you need is a millimeter ruler and a mirror.

1. Stand facing a mirror, about 20 cm (8 inches) away.
2. Hold a millimeter ruler horizontally just below your eyes.
3. Close your right eye. Align the zero mark with the center of your left pupil.
4. Open your right eye and close your left. Read the measurement in front of your right pupil.
5. Look straight ahead (into the distance, not at the ruler) to avoid eye convergence.

Repeat the process 2 to 3 times and average the results for greater accuracy.

Not confident in your measurement? Send us a photo and our team will calculate your PD with precision.

1. Hold a standard credit card horizontally just below your nose — it will serve as a scale reference.
2. Ask someone to photograph you straight on, from 3 meters (10 feet) away, with the flash enabled to illuminate your pupils and get a sharp reflection.
3. Look directly into the camera lens.
4. Send the photo to Gunnar support — we'll get back to you with your PD within 24 hours.

Do not take a selfie with your arm extended. The lens distortion at close range significantly skews the measurement. The photo must be taken from 3 meters away by another person.