PD : Easy Pupillary Distance is a free utility and tools application available on the iPhone platform. Developed by Zernike LLC, this program offers various features related to pupillary distance (PD) measurement, segment height measurement, and optical math calculations.

With PD : Easy Pupillary Distance, users can instantly measure PD by capturing a single high-resolution facial photo. The app guarantees the best possible measurement accuracy using the device's camera system. It provides distance, intermediate, and near PD values, both binocular and monocular, at no cost.

In addition to PD measurement, the app also allows users to measure segment height for frames they are currently wearing. This is done by capturing a single high-resolution facial photo. It's important to note that segment height measurement is currently supported only on devices equipped with the TrueDepth or LIDAR camera systems, such as iPhone X.

Furthermore, PD : Easy Pupillary Distance offers a range of optical math calculations, including Rx transposition, vertex conversion, keratometry conversion, visual acuity scale, minimum blank size (MBS), simple magnifier, and spectacle magnifications.

Overall, PD : Easy Pupillary Distance is a handy utility for anyone in need of accurate PD measurement, segment height measurement, and optical math calculations. Its user-friendly interface and high-resolution photo capture make it a convenient tool for opticians, eyewear professionals, and individuals who require precise measurements for their eyewear needs.