How to Choose Kids’ Glasses by Pupillary Distance (PD)

What Is PD? 

Pupillary Distance (PD) is the space between the centers of the pupils (in millimeters). It ensures the optical center of each lens lines up perfectly with your child’s eyes. A properly matched PD means clear, comfortable vision.

PD to Frame Size Conversion Chart

PD Range (mm)

Recommended Frame Size

< 42 mm

35–37 mm

42–48 mm

37–38 mm

49–52 mm

40–42 mm

53–55 mm

43–45 mm

56–58 mm

45–47 mm

59–62 mm

47–52 mm

You’ll often find PD included in a prescription or measured in-store. Even a few millimeters off can lead to distortion or strain.

 

 

Why PD Matters

· Visual Accuracy: Keeps lenses aligned with your child’s actual line of sight.

· Better Comfort: No blurry zones, no double vision.

· Personal Fit: Especially important if you’re buying glasses online.

How to measure PD？

Already Know and Go to Pick up the Frames.