About
PD+ is a powerful iOS application designed to accurately measure pupillary distance (PD) and fitting heights using the camera system on your iPhone, iPad, or Mac. By capturing a single high-resolution facial photo, the app leverages advanced image processing and computer vision to deliver the highest measurement accuracy achievable by your device's camera. Far and near PD measurements—both binocular and monocular—are available at no cost, making it accessible for anyone ordering glasses online or working in an optical setting. For devices equipped with TrueDepth or LiDAR camera systems (iPhone X and later non-SE models), PD+ also measures fitting heights—a critical measurement for properly centering lenses within frames and positioning segments for multifocal lenses. Beyond measurements, PD+ includes a comprehensive set of optical calculators: Rx Transposition, Vertex Adjustment, Crossed Cylinders (over-refraction), Keratometry Conversion, Visual Acuity Scale, Estimated Visual Acuity, Minimum Blank Size (MBS), and magnification tools. These make it an invaluable pocket reference for optical professionals such as opticians, optometrists, and optical lab technicians. With a 4.7-star rating and voice-guided instructions, PD+ is user-friendly for both consumers looking to order prescription glasses online and eyecare professionals who need quick, reliable measurements in the field.
Key Features
- Instant PD Measurement: Measures far and near pupillary distance (binocular & monocular) from a single high-res photo using your device's camera.
- Fitting Height Detection: Accurately determines lens fitting heights on your frames using TrueDepth or LiDAR camera systems (iPhone X and later non-SE models).
- Optical Calculators Suite: Includes Rx Transposition, Vertex Adjustment, Crossed Cylinders, Keratometry Conversion, Visual Acuity, MBS, and magnification calculators.
- Voice-Guided Instructions: Step-by-step voice guidance walks users through the measurement process for ease of use and accuracy.
- Multi-Device Support: Compatible with iPhone, iPad, and Mac, adapting measurement precision to the capabilities of each device's camera system.
Use Cases
- Consumers measuring their own pupillary distance before ordering prescription glasses online without visiting an optician.
- Opticians and optical technicians using the app as a quick field tool for PD and fitting height measurements.
- Optical students and professionals referencing the built-in calculators for Rx Transposition, Vertex Adjustment, and other common optical computations.
- Multifocal lens fitters determining accurate segment heights using the fitting height feature on LiDAR-equipped devices.
- Patients or caregivers measuring PD for a family member's eyeglass prescription in remote or underserved areas.
Pros
- High Accuracy on Modern Devices: Devices with TrueDepth or LiDAR cameras (iPhone X+) deliver reliable, precise measurements suitable for ordering prescription lenses.
- Free Core Features: Far and near PD measurements (binocular & monocular) are available at no cost, providing strong value without a paywall.
- Comprehensive Optical Toolset: The built-in calculator suite makes it a useful all-in-one reference tool for optical professionals on the go.
Cons
- Reduced Accuracy on Older Devices: Single-lens cameras on models like iPhone SE lack depth imaging, leading to PD measurements that may be off by 4–6 mm.
- Fitting Height Requires Specific Hardware: Fitting Height measurement is only supported on devices with TrueDepth or LiDAR cameras, limiting availability for some users.
- Not a Substitute for a Professional Optician: For critical prescriptions, results should be verified by a licensed optician, especially on non-TrueDepth/LiDAR devices.
Frequently Asked Questions
Is PD+ free to use?
Yes, the core PD measurement features (far and near, binocular and monocular) are free. Additional features may be available via in-app purchase.
Which devices support fitting height measurement?
Fitting height is currently supported only on devices with TrueDepth or LiDAR camera systems, such as iPhone X and later non-SE models.
How accurate is PD+ compared to an optician?
On compatible devices (TrueDepth/LiDAR), PD+ delivers high accuracy. On older single-lens devices like iPhone SE, measurements may deviate by 4–6 mm, so professional verification is recommended for critical prescriptions.
What optical calculators are included in PD+?
PD+ includes calculators for Rx Transposition, Vertex Adjustment, Crossed Cylinders (over-refraction), Keratometry Conversion, Visual Acuity Scale, Estimated Visual Acuity, Minimum Blank Size (MBS), and magnification.
Does PD+ work on Mac and iPad?
Yes, PD+ is compatible with iPhone, iPad, and Mac, though measurement capabilities may vary depending on the camera hardware of each device.
