How to Measure Pupillary Distance (PD) for Eyewear
Pupillary distance (PD) is a crucial measurement when ordering prescription eyeglasses or sunglasses. It ensures that your lenses align correctly with your pupils, providing optimal vision. Let’s dive into the details:
What Is Pupillary Distance (PD)?
- PD is the distance between your eyes’ pupils, expressed in millimeters.
- Opticians typically measure PD during an eye exam using a pupillometer.
- Sometimes, your prescription includes PD, but not always.
Why Is PD Important?
- Eyeglass lenses have an “optical center,” the ideal spot for your pupils to look through.
- Accurate PD ensures that your lenses align correctly with your pupils, reducing eye strain and improving vision.
Methods to Measure PD:
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Mirror Method:
- Stand about 8 inches/20 cm away from a mirror.
- Hold a millimeter ruler horizontally just above your eyes, flat against your eyebrows.
- Close your right eye and align the ruler’s zero mark with the center of your left pupil.
- Open your right eye and look straight ahead.
- Close your left eye and note the reading directly over your right pupil. That measurement is your total PD.
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Single PD vs. Dual PD:
- Single PD (Binocular PD): Measures the distance from the center of one pupil to the other.
- Dual PD (Monocular PD): Measures the distance from each pupil to the bridge of your nose (e.g., 31/30 mm for each eye).
- For reading glasses, subtract 3 mm from your single PD (or 1.5 mm from each eye’s number in your dual PD) to get your “near PD.”
Tips for Accurate Measurement:
- Use a ruler marked in millimeters or an online tool.
- Stand in front of a mirror.
- Measure the distance between the centers of your pupils.
- Repeat several times for accuracy.
Remember, having an accurate PD measurement ensures your glasses fit perfectly and provides optimal visual comfort! 😊
Here is available KUGO PD Ruller for printing in EN , SK versions.