What is a single vs dual pupillary distance?
Single PD
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
DUAL PD, or monocular pupillary distance, is the distance from the center of one pupil to the bridge of your nose. Dual PD has two numbers showing the right eye (OD) and the left eye (OS) measurements.
How to find yours
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!
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Glasses Method
What you will need
1. Position yourself
With glasses on, focus on an object 20 feet away or on a close object for near-sighted.
2. Mark your glasses
Mark a dot over the right lens over the object then do the same for the left lens.
3. Measure
Measure the distance between the two dots by aligning the 0 mm line with one dot. The second dot is your PD.
Ruler method
What you will need
1. Position yourself
Position yourself approximately 8 inches (20 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 your right and left pupil. The number over your left pupil is your PD.
With the help of a friend
What you will need
1. Face your friend
Position your friend out of your field of vision. Focus on an object from 10-20 feet away.
2. Center your ruler
Have your friend align the 0 mm over the center of your right pupil.
3. Measure
Measure the distance from your right and left pupil. The number over your left pupil is your PD.
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Friendly reminder
Print PD ruler at 100% size. Do not use scaling or fit setting. Print setting shoud be actual size.
Measure against a millimeter ruler to assure printout is accurate.