Pupillary Distance (PD): Precision for Clear Vision

Pupillary Distance (PD) measures the distance between the centers of your pupils in millimeters. A precise PD ensures that your eyes align with the optimal focal point of your lenses, providing the best clarity and comfort.

For most adults, PD ranges between 55-75mm, while for children, it falls between 42-58mm. If your prescription doesn’t include a PD measurement, you can check with your eye doctor or measure it yourself to ensure the best fit for your glasses.

Single PD: Understanding Your Pupillary Distance

If your prescription includes just one PD number, known as Single PD, it represents the total distance between your pupils. This is typically your distance PD, unless specifically noted as a near/reading PD.

For most people, distance PD ranges between 40-80mm. If you need a near PD for reading glasses, you can calculate it by subtracting 3mm from your distance PD.

Dual PD: A More Precise Measurement

If your PD is given as two numbers, known as Dual PD, it represents the distance from the center of each pupil to the bridge of your nose. This measurement provides a more precise fit for your lenses.

Dual PD is typically written as 32/30, where the first number refers to the right eye (OD) and the second to the left eye (OS). Each value is usually less than 40mm.

How to Calculate Near PD for Reading Glasses

To determine your Near PD for reading glasses, simply subtract 3mm from your Distance PD.
Example: If your Distance PD is 63mm, your Near PD would be 60mm.
If you have Dual PD, subtract 1.5mm from each eye’s measurement.
Example: If your Dual PD is 33/31mm, your Near PD would be 31.5/29.5mm.
This adjustment ensures optimal lens alignment for close-up vision.