Pupillary distance (PD) is quite simply the distance between your two pupils. Your PD is measured in millimeters and is necessary for creating your custom prescription eyeglasses. Your PD allows an optician to properly position your lenses within a frame of your choice in order for you to see.
Typically, most adults have PDs between 55-65 mm. For kids, PDs are usually between 42-54 mm.
You can often get your PD measurement from your doctor or a licensed optician. However, pupillary distance is also easy to measure yourself! With a pupillary distance ruler (in other words, any millimeter ruler), you can measure the distance between the center of your pupils yourself in a mirror or have a friend help out.
This video explains what a PD (Pupillary Distance) is and how to measure it.
Concerned about you or your friend measuring accurately? We get it - it’s an important measurement, and your eyesight depends on it. That’s why we’ve developed AccuPD.
AccuPD is our free interactive tool that allows you to measure your own pupillary distance right from your phone! The doctors behind 39DollarGlasses.com developed this PD measurement tool as part of our continued efforts to make shopping for prescription glasses easy and affordable.
Getting an accurate PD measurement is now even easier than taking a selfie, thanks to AccuPD from 39DollarGlasses.com. All you’ll need is your smartphone and a credit card (or another card that’s the same size).
Typically, there will only be one number in your PD measurement - this is called Single PD, and it can be used to order most types of prescription eyeglasses.
But if you have two different numbers, you have been measured for Dual PD (also known as monocular PD). In this scenario, the numbers are measurements of the distances from each pupil to the bridge of your nose - the first number refers to the left eye distance, and the second to the right. Added together, these numbers should equal the full distance measured between your two pupils. Dual PD is required for reading glasses, but not usually necessary otherwise.
Your prescription provides us with your doctor's recommendation for clear and comfortable vision. Please take a brief moment now to review your information with our 3 samples shown here. They represent 3 different ways of writing the same prescription:
01. Your astigmatism correction ("cylinder"). Some doctors write their prescriptions in plus (+) cylinder and some in minus (-) cylinder. They are not the same. Take special note of this when entering your prescription later. If you don't see anything there, leave it blank.
02. "dist" (distance) is often abbreviated "D.V."
03. "near" (reading) is often abbreviated "N.V."
04. For reading-only glasses: Some doctors will write the reading prescription separately, in its entirety (as "NEAR" or "N.V." or "N.V.O."), as in SAMPLE Rx #3. If this is the case, enter the power in the BOTTOM half of the form (you'll see; it's easy), and leave the ADD power blank ("0.00").
If you do not understand ANY part of your prescription, please call us to ensure everything is entered correctly. Don't be shy; we are here to help, and we want your glasses to be made exactly to your doctor's specifications.
OD = Right Eye
OS = Left Eye
OU = Both Eyes
01. Your doctor may use a blank Rx pad, not a pre-made Rx pad for eyeglasses only. If this is the case, you can draw imaginary grid-lines to separate the numbers. It will separate the different values more easily for you. The top power is always the right eye & the bottom power is always the left.
02. If you don't see numbers in some of the boxes (if there is no CYL or AXIS or ADD), leave those values blank when ordering. If you only see one number for each eye, it's the "SPHERE" power; leave all the other fields blank.
03. It is common for the doctor to sometimes leave out the decimal points. If you see a number like -25 or +175, it is understood that your doctor means -0.25 or +1.75, respectively. Also, an axis of 5 (or 05) is the same as 005; 90 is the same as 090. It's like using abbreviations or writing in short-hand.
04. If you have no astigmatism in one or both eyes, your doctor may just write the sphere power alone, or may use placeholders like sph ("sphere") or D.S. ("diopters sphere") instead.
05. If you have a prescription for bifocals, and you only see one ADD power, it's understood that you have the same ADD for both eyes. If you don't see an ADD power, leave it blank.
06. Some common prescription abbreviations:
If you still do not understand ANY part of your prescription, please contact us to ensure everything is entered correctly. Don't be shy; we are here to help, and we want your glasses to be made exactly to your doctor's specifications.
This measurement is necessary to ensure the correct positioning of your lenses within the frame you have chosen. Have a friend* measure the distance from the center of the pupil (black dot) in one eye to the center of the pupil in the other eye. It's like measuring a line connecting the two black dots.
To measure your PD:
01. Place the millimeter ruler on the bridge of your nose.
02. Have a friend face you about arms length away.
03. Have your friend measure the distance between the center of your pupils (the black dots in the middle of your eyes).
04. (Or you can do it yourself simply by looking in the mirror).
You can also get this information from your doctor or from a licensed optician.
As a guideline:
+ Most adults' PD's are between 55-65.
+ Most kids' PD's are between 42-54.