How to Measure Pupillary Distance (PD) at Home for Your Child: A Quick Guide

Knowing how to measure pupillary distance for kids is key to ensuring their glasses fit correctly. This quick PD measurement at home guide will help you align lenses for the best kids glasses fitting.

What is Pupillary Distance (PD)? 

Pupillary Distance (PD) is the distance in millimeters between the centers of your child’s pupils. It helps opticians place the optical center of each lens directly in front of the pupil. A correct PD ensures your child sees clearly and comfortably through their glasses.

How to Measure Pupillary Distance at Home

You don’t need special tools—just a millimeter ruler and follow the steps!

Tip: Stand about 8 inches (20 cm) from your child to measure more easily.

Steps:

1. Have your child stand or sit still and look straight at a distant object.

2. Hold the ruler on the bridge of their nose, directly in front of their eyes.

3. Measure from the center of one pupil to the center of the other (this is the PD).

4. Repeat 2-3 times to ensure accuracy.

✅ Extra Tips for Accurate PD Measurement

· Use a well-lit room to clearly see their pupils.

· Make sure your child’s head is straight and still.

· Always measure in millimeters for precision.

· Ask a partner to help hold the ruler while you read the numbers.