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How to measure PD, Dual PD and SH with Optigrid

How to Use Optigrid for Accurate PD, Dual PD, and Segment Height Measurements

Optigrid is an innovative tool designed to enhance the accuracy and efficiency of eyeglass prescription measurements directly from patient photos. This step-by-step guide will walk you through the process of using Optigrid to measure Pupillary Distance (PD), Dual PD, and Segment Height (SH), ensuring precise results for custom eyewear orders.

Step 1: Load the Patient Photo

Begin by uploading the patient’s photo into the Optigrid system. Ensure the photo is recent and clearly shows the patient’s face.

Step 2: Evaluate the Photo Quality

For Optigrid to work effectively, the photo must meet certain criteria:

  • Distance: The photo should be taken from approximately 1 meter away. This is roughly equivalent to 3.28 feet, ensuring an optimal perspective for measurement.
  • Clarity: Ensure the photo is not blurry. A clear image is crucial for precise measurements.
  • Orientation: The patient must be looking straight at the camera, with their head neither twisted nor bent. This positioning is essential for accurate alignment during measurements.

Step 3: Choose a Reference

Optigrid allows you to select a reference object to calibrate the measurement scale. You can choose from preconfigured references, such as a credit card size, or use a custom reference by entering its size in millimeters (mm).

Step 4: Mark the Reference Points

Using your mouse, click on the designated points of the reference object within the photo. This calibration step is crucial for ensuring the measurements are scaled correctly.

Step 5: Locate the Pupils

Click the “eye” button in Optigrid, then use the mouse to mark the center of each pupil. Accuracy here is vital, as this determines the PD measurement. You can adjust the crosshair placement if necessary for precision.

Step 6: Measure Dual PD

Select the “center” button, then position the vertical line precisely in the center of the nasal bone, between the eyes. This step is necessary for measuring Dual PD, which is essential for ensuring lens alignment with the patient’s eyes.

Measure PD and Dual PD with center line

Step 7: Determine Segment Height (SH)

If the patient is wearing their frame in the photo:

  • Click the “base” button.
  • Use the mouse to align the horizontal line with the bottom edge of the frame. This action is crucial for measuring the Segment Height (SH), important for multifocal lens placement.

Step 8: Measure PD, Dual PD, and SH

Once all points are correctly set, press the “calculate” button. Optigrid will now compute the PD, Dual PD, and SH based on your inputs.

Step 9: Verification

It’s essential to double-check the measurements provided by Optigrid. Ensure that all reference points were marked accurately and that the calculated values seem consistent with the patient’s needs.

Step 10: Save and Proceed

After verifying the accuracy of the measurements, save them to the patient’s profile. You are now ready to proceed with the eyewear order, equipped with precise measurements for a perfect fit.


Congratulations! You’ve successfully navigated the process of measuring PD, Dual PD, and SH using Optigrid. This tool not only simplifies the measurement process but also enhances the accuracy of eyewear prescriptions, ensuring patients receive the best possible fit for their glasses.

Remember, practice makes perfect. The more you use Optigrid, the more efficient and accurate your measurements will become, leading to satisfied customers and high-quality eyewear.