PD: Pupillary Distance

Why is PD Important for Your Glasses?

Think of your prescription glasses as a window to the world. Your Pupillary Distance (PD) is like the frame that ensures this window aligns perfectly with your eyes, providing the sharpest and most comfortable view possible. When the PD is accurate, you enjoy crystal-clear vision, reduced eye strain, and a truly seamless viewing experience. On the other hand, if the PD is incorrect, it’s like looking through a misaligned window, leading to blurred vision, headaches, and eye fatigue.​​

An accurate PD is the key to ensuring your glasses provide maximum clarity, allowing you to not only look your best but also see your best!

PD Measurements: A Quick Guide

• Single PD is a measurement of the distance between the centers of your pupils. It's typically expressed as a single number, like "62 mm."

• Dual PD measures the distance from the center of each pupil to the bridge of your nose. It's usually expressed as a pair of numbers, like "32/30 mm," where the first number is for the right eye (OD) and the second is for the left eye (OS).

• Distance PD vs. Near PD: Some eyeglass prescriptions may include both a distance PD and a near PD, like "63/60."

  • Distance PD: Used for ordering single vision distance, bifocal, and progressive glasses.

  • Near PD: Used for ordering single vision reading glasses.

• Dual PD Limits: To ensure optimal vision and comfort, the difference between your right and left dual PD measurements should not exceed:

  • 3 mm for progressive or bifocal lenses.

  • 5 mm for single vision lenses.

Need Your PD? We've Got You Covered!

Your optician usually measures your PD before ordering glasses. But if you don't have that information, no worries! Our easy-to-use digital PD tool makes it simple to measure your PD yourself, without a ruler.

Here's how it works:

• Find a well-lit spot: Good lighting makes the process easier.

• Remove your glasses: A clearer view ensures accurate measurements.

• Center yourself: Look directly at your screen and adjust the camera as needed.

• Grab a card: Find a standard credit card or similar card with a magnetic strip.

• Snap a photo: Place the card against your forehead and take a picture.

That's it! Your PD measurement will be displayed on the screen.

​​​Click here to learn more and try our easy-to-use online PD ruler.