# What is pupillary distance (PD)?

> Pupillary Distance is the distance in millimeters between your pupils This measurement tells us where to focus your prescription in the lens We will need one 

Source: https://support.roka.com/en_us/what-is-pupillary-distance-pd-SkYfgdI1Wg

Last updated: 2025-12-04T19:25:10.635Z

Pupillary Distance is the distance in millimeters between your pupils. This measurement tells us where to focus your prescription in the lens. We will need one to accurately input your prescription An inaccurate measurement can result in blurry vision or double images, but a variance up to two millimeters is OK.

If you have a right and left PD, please select I have two PD's and enter right then left. 

You can find your PD by downloading [PDCheck AR](https://apps.apple.com/us/app/pdcheck-ar/id1563806777) for iPhone or [GlassesOn](https://play.google.com/store/apps/details?id=com.sixoversix.copyglass&hl=en_US) for Android

You may also be able to contact your eye doctor to get your measurements from them.