What is PD?
PD stands for Pupillary Distance, which is the distance between your pupils in millimeters. PD is very important for accurately fitting your lenses to achieve visual acuity.
Generally, PD numbers do not change for adults. The average PD range for adults is 55-75 mm and for kids is about 42-55 mm. A difference of 2-3 mm is acceptable.
How to measure PD?
We highly recommend checking your PD with your doctor, especially for bifocal or progressive lenses.
You can also measure the PD by yourself.
1.Print our downloadable PD ruler
|2.Place the ruler directly over the center of your right pupil so that the ruler is horizontal. Place against forehead for added stability. Stand in front of a mirror, or ask someone else to measure for you.|
|3.While looking straight ahead, measure the distance from the center of your right pupil to the center of your left pupil.|
|4.Repeat a couple of times for accuracy and use an average for your final measurement.|
How to read PD?
Your PD may be written in three ways:
1. PD (OU), written as "64", means the Binocular PD which is for both eyes.
2. PD (OD), means the Monocular PD for the right eye. PD (OS), means the Monocular PD for the left eye.
A Monocular PD is written as two numbers, for example, "32/32", the first one "32" represents the PD for the right eye, and the second one "32" represents the PD for the left eye.
3. Sometimes PD is written with two different numbers, for example, "62/59", or they are labelled "Far" and "Near". Your PD is usually measured for distance vision, which is 'Far PD", or "62" in this example. For reading glasses, doctors measure your "Near PD" or "59" in the above example.
Always enter your "Far PD" for distance vision eyeglasses and enter your 'Near PD" for your reading glasses only. For most people, the difference between Far PD and Near PD is about 2-3mm.
How to fill in PD?
1. If you only have one PD number, such as "64", please select 64 when fill in your prescription.
2. If you have two numbers in your prescription, such as "32/32", please click "Two PD numbers?" and fill in 32/32.
3. If your PD is written as "62/59", then "62" is your far PD and "59" is your near PD. Please enter your "Far PD" for distance vision eyeglasses and enter your 'Near PD" for your reading glasses only.