# How to measure your Pupillary Distance (PD)

## What is Pupillary Distance?

PUPILLARY DISTANCE (PD) measures the distance between the centers of your pupils. This measurement is used to determine where you look through the lens of your glasses or VR insert and should be as accurate as possible. The average adult’s PD is between 54-74 mm.

## What is the most accurate way of measuring my PD?

The most accurate way of measuring your PD would be to contact your optician to get them to measure your PD for you.

## Single PD vs Dual PD

SINGLE PD is the pupillary distance between the center of one pupil to the other, which can be a distance PD or near PD. Distance PD can be used to order any type of prescription glasses except reading glasses. Read below to learn how to calculate near PD for reading glasses.

DUAL PD, or monocular PD, consists of two numbers and is the distance between the centers of each pupil to the bridge of the nose. Dual PD is usually written in the following notation: 32/30. The first number is always the right eye (OD) measurement, and the second number is the left eye (OS).

How Do You Calculate Near PD For Reading Glasses?

You can calculate Near PD for reading glasses by subtracting 3mm from your distance PD. For example, if your distance PD is 63mm, then your near PD is 60mm.

## How do I measure my own PD?

Your prescription may tell you your PD. However if your PD measurement is not available, follow the guide below.

#### Step-by-step guide on how to measure your PD with the help of a friend:

1. Keep both eyes open

2. Have your friend put the zero on the millimeter ruler over the center of one pupil.

3. Measure the distance to the center of the other pupil.

#### Tips to get an accurate measurement

• Have them crouch/sit while you stand so they are out of your field of vision.
• Keep your eyes as still as possible.
• Look above his/her head at something approx 10-20 ft. away.
• Do not look at the person measuring!
• Take 2-3 measurements to check the accuracy.

## Any questions?

If you need help, you can send us a message via the live chat or get in touch on support@adlens.com