Read the labels before choosing dual PD
When ordering glasses online with two PD numbers, do not assume every pair of numbers means the same thing. A measurement labeled right and left describes separate eyes. A document labeled distance and near describes different viewing tasks instead.
Check the headings and units on the original document. If the numbers appear without labels, ask the professional who measured them what they represent. Guessing from the size of a number is not a substitute for confirmation.
The FTC’s prescription-shopping guidance explains that PD is needed when fitting glasses. Our missing-PD guide covers what to do if you do not have the measurement.
A labeled right-and-left example
Suppose your measurement explicitly says right 31.5 mm and left 32 mm. Choose the checkout’s dual-PD option and put each value in the matching eye’s field. The values do not need to be equal.
Those example values add to 63.5 mm, but a total does not retain the separate right and left information. When you have labeled dual measurements, use the dual fields. Do not average them into two identical values or round a decimal to simplify the entry.
The example is arithmetic, not a measurement recommendation. Use your own measured values. If a value is outside the available choices, contact us before ordering rather than picking the nearest one.
Keep near and distance information separate
If the document gives a distance PD and a near PD, do not enter them as right and left. Confirm the measurement for the task you are ordering. A reading pair and a distance pair are different configurations.
At checkout, answer the reading-use and prior-PD-adjustment question accurately. Do not apply another reading adjustment to information that was already prepared for that task. Our reading and computer comparison explains why the actual working distance matters.
You can upload a clear prescription with PD and select the option indicating that the measurement is on the document. Include the labels, not a cropped image of the numbers alone.
Check the rest of the custom order
Copy SPH, CYL and any AXIS separately for each eye. PD does not replace those prescribed lens values. Check frame dimensions against a comfortable pair and read the custom-order return terms before paying.
Fast Eyeglasses offers eligible corrective single-vision pairs, not bifocals, progressives, prism or fully nonprescription plano pairs. Everyday base pairs start at $79; upgrades and applicable stronger-prescription charges are extra.
Save the confirmation and measurement together. A careful label check now is simpler than explaining an uncertain entry after custom lenses have been made.
Common buying questions
Should I add two PD numbers together?
First confirm their labels. If they are right and left measurements, use the dual-PD fields to preserve that information. Near and distance values must not be added together.
Can right and left PD measurements be different?
Yes. Use the measured values for their labeled eyes rather than making them equal.