How to Measure Your PD
“PD” stands for “pupillary distance,” the distance between your pupils in millimeters. We use this measurement to make sure the centers of your lenses are correctly aligned with your pupils.
Call Your Optometrist
Any optometrist or optician you have used in the past should have a record of your PD. A PD measurement taken years ago is still good; PD does not change for adults. So learning your PD may be as simple as making a phone call. Many optometrists and opticians are happy to give you the information; after all, you paid them for their services.
However, unfortunately, some optometrists and opticians will refuse to provide your PD because they don’t want to lose your business. If you can’t obtain your PD from your optometrist, here are a couple of other simple suggestions:
Ask an Optician to Measure Your PD:
Many opticians are happy to measure your PD for free or for a small fee. Our customers tell us that the optical stands at some of the large “big box” stores and department stores are especially glad to provide this service.
Send Us a Pair of Old Glasses:
Send us an old pair of your prescription glasses and we will measure it ourselves. Include a note with your name, telephone number, email address and the date you submitted your online order. We will return the old glasses with the new glasses we create for you. Remember, your PD doesn’t change, so any pair of eyeglasses that once gave you a good correction will work fine. [Need to add instructions on how to send the glasses.]
Two PDs
If you need to measure your own PD, it’s not hard to do. Actually, you have two PDs: your “distance PD” and your “near PD.” When you focus on a close object, your pupils move slightly closer to each other, resulting in a slightly lower PD.
Many optical companies, including most of our online competitors, ask for just one PD measurement. At MyGlasses.com, our goal is to provide the highest quality prescription lenses with the absolute best correction possible. Our customers will tell you that the lenses we provide often surpass the quality of lenses they have previously obtained at brick and mortar stores.
One example of our attention to quality and detail is our request for two PD measurements for some lens types. Here’s what we request, depending on the kind of glasses you are ordering:
Type of lenses / PD measurement requestedReaders / near
Single Vision for Near / Near
Single Vision For Intermediate / Distance or Near
Single Vision For Distance / Distance
computer/office / distance + near
progressive / distance + near
MEASURING YOUR DISTANCE PD
Here are three methods to measure your distance PD. Each of these methods is simple and accurate. Use whichever method is most convenient for you. For peace of mind, measure your PD using more than one method to confirm your results.
Regardless of the method used, your measurement should be in millimeters and should fall within the range of 48 to 75 mm, with an average of about 60 mm for women and 64 for men.
Method 1: The Old Glasses Method
1. Put on a pair of glasses. Any glasses will do -- your current glasses, a previous pair of glasses or even someone else’s glasses. Hold your head straight and make sure the glasses are setting as you would normally wear them.
2. Have a marker handy. It can be a non-permanent marker, a “white-out” marker, or a make-up pencil.
3. Have something handy to cover one eye, such as an index card or a magazine.
4. Focus on an object in the distance. Don’t focus on something too close.
5. While covering your left eye (don’t close it; just cover it up), use your marker to put a dot on your right lens so that the dot is directly over the object you are looking at.
6. Do the same for the left eye.
7. If you have done those steps correctly, when both eyes are open and focused on the distant object, the two dots should appear as one single dot.
8. Using a millimeter ruler, measure the distance between the two dots. Remember, we want your PD in millimeters. The distance between those two dots is your distance PD.
Method 2: The Black Strip Method
1. Using a piece of black or dark paper, measure a strip that is exactly 60 millimeters long and about half an inch wide. After you have cut out the paper strip, double check to make sure it is exactly 60 millimeters.
2. Tape the black strip to your forehead so that it is centered over both eyes, just above your eyebrows.
3. Have a friend take a photo of your face. Stand at least five feet away from the camera and look straight into the camera. Ask your friend to use the zoom to take a picture of your face. The black strip gives us the scale we need to measure your PD.
4. Attach the photo to an email and send it to . In the body of the email, provide your order number, your name, telephone number, email address and the date you placed your online order.
Method 3: The Compass Method
Find a compass -- not the kind that points north, but the kind you used back in geometry class.
Stand in front of a mirror, more than three feet away to get a distance PD. Then, while observing your reflection in the mirror, adjust the two compass points until they are directly in front of your two pupils. Hold the points close to your pupils, but don’t poke yourself. Now use your millimeter ruler to measure the distance between the two points.
MEASURING YOUR NEAR PD
If you are ordering readers, computer/office or progressive lenses, we also request your near PD. Here’s how to measure that:
Method 1: The Old Glasses Method:
Follow the Old Glasses Method described above. However, at Step 4, instead of focusing on an object in the distance, stand in front of a mirror, no more than 3 feet away, and look at your reflection.
Then, while covering one eye, use your marker to place a dot on your other lens, exactly at the center of your pupil. Repeat with the other eye. Using a millimeter ruler, measure the distance between the two dots. That is your near PD.
Method 2: The Black Strip Method:
Follow the Black Strip Method described above. Except this time, stand much closer to the camera. Pretend the camera is a book or computer screen and try to read it. When you send us that photo, make sure to mention in your email that it was taken for a near PD measurement.
Method 3: The Compass Method:
Follow the Compass Method described above. However, this time stand as close to the mirror as you can, as close you would if the mirror was a book or a computer screen.
After you have obtained or measured distance and/or near PD measurements or have taken the necessary photos, provide the necessary information on this PD form: