Your Pupillary Distance, or PD, is the distance in millimeters (mm) between the center of one pupil to the center of the other. A personalized fit starts with measuring your pupillary distance, indicating which part of the lens you look through, ensuring optimal comfort and clarity.
If your PD isn't right, it can cause eye strain, fatigue, or inability to see properly. The higher your prescription, the bigger the effect an incorrect PD can have. So get measuring!
SINGLE PD, or binocular pupillary distance, is the standard measurement of the distance from the center of one pupil to the other. Distance PD can be used to order any type of prescription glasses except reading glasses.
DUAL PD, or monocular pupillary distance, is the standard measurement of the distance from the center of each pupil to the center of the bridge of your nose. Dual PD has two numbers showing the right eye (OD) and the left eye (OS) measurements.
To obtain your PD measurement, simply ask your eye doctor to include it in your prescription. Alternatively, you can use one of the following methods to measure it yourself. Super easy!
With just a few clicks, OPTHY measures your Pupillary Distance so you get the perfect fit. Discover more
What you will need
1. Position yourself
Position yourself approximately 12 inches (30 cm) away from a mirror.
2. Look in the mirror
Look straight ahead into the mirror and position the ruler over the bridge of your nose.
3. Measure
Close your left eye and align the 0 mm over the center of your right pupil. Measure the distance from the center of your right pupil to the center of your nose. Repeat with your left eye.
4. Write it down
If the PD value is the same for both eyes, add them together to get a single PD. If the PD values are different, mark both values. This means you have a dual PD and you will need to enter them separately.
1. Face your friend
Make sure your friend is standing in front of you, at a 16-20 inches (40-50 cm) distance (it should be the length of your friend's arm stretched out).
2. Center your ruler
Have your friend align the ruler over the bridge of your nose. The 0 mm should be over the center of your right pupil.
Look straight ahead and ask them to measure the distance from the center of your right pupil to the center of your nose. Repeat with your left eye.
If the PD value is the same for both eyes, add them together to get a single PD. If the PD values are different, have your friend mark both values. This means you have a dual PD and you will need to enter them separately.