How to Measure Your Pupillary Distance
Your pupillary distance, often referred as just PD, is simply the distance measured between the center of each pupil. You can find your pupillary distance on your prescription or you can measure it yourself.
Finding Your PD by Prescription
Your PD will be written towards the bottom of your prescription. The value will range between 50mm to 70mm, with the most common value being 62mm. If your PD contains two numbers, for example 62/60, this means your distance PD is 62 and your near PD is 60. The near PD is only required when ordering bifocals or progressive lenses.
Measuring Your Own PD
First, you'll need a ruler that shows millimeters. Place this ruler on your nose so that the starting point of the ruler is at your right or left eye's pupil.
Now measure the distance between the left and right pupil. Use a mirror or ask a friend to help. Make sure you look straight ahead and repeat your measurement to get an accurate number.
Measuring your own PD is very simple and it's better than just using a typical average value instead. But, nothing beats getting a prescription from your eye doctor or optician if you have a progressive or bifocal prescription.