How to Measure Your Pupillary Distance (PD) at Home

Understanding Pupillary Distance

Pupillary Distance, usually shortened to PD, is the measurement in millimeters between the centers of your pupils. It helps position your lenses correctly in front of your eyes for a clearer and more comfortable viewing experience.

Visual guide showing how to measure pupillary distance at home with a millimeter ruler.

Why Is PD Important?

An accurate PD measurement helps:

• Position the lenses correctly within the frame
• Reduce possible visual discomfort caused by poor lens alignment
• Support clearer and more comfortable everyday vision

Measuring Your PD at Home

Quick tip: Adult PD measurements commonly range from 54–78 mm. Measure your PD two or three times and compare the results before submitting your order.

Step 1: Get Ready

Stand approximately 8 inches or 20 centimeters away from a mirror. You may also ask another person to help.

Hold a millimeter ruler horizontally against your brow and keep your head facing straight ahead.

Visual guide showing the correct ruler position before measuring PD.

Step 2: Set the Starting Point

Close your right eye while keeping your left eye open.

Move the ruler until the 0 mm mark is aligned with the center of your left pupil. Keep both the ruler and your head steady.

Visual guide showing the 0 mm mark aligned with the left pupil.

Step 3: Find Your Total PD

Without moving the ruler, open your right eye and close your left eye.

Read the millimeter number positioned directly over the center of your right pupil. This measurement is your Total PD.

Visual guide showing how to read the total PD at the right pupil.

Step 4: Measure Dual PD (Optional)

Some orders may require separate PD measurements for each eye.

Measure from the center of your nose bridge to the center of each pupil:

• OD: Right-eye PD
• OS: Left-eye PD

Add the right and left measurements together to calculate your Total PD.

Visual guide showing separate right-eye and left-eye PD measurements.

Final Measuring Tips

• Repeat the measurement two or three times
• Compare your results and use the most consistent reading
• Keep the ruler straight and your head level
• Use bright, natural lighting when possible
• Look forward instead of following the ruler with your eyes
• Ask an optical professional for help with children or more complex prescriptions