What is PD (Pupillary Distance) and Why is it Important for Eyewear Fitting?

July 31, 2024

Have you ever wondered why, when getting new glasses at an optical store, the staff may use a device that looks similar to binoculars, a ruler, or mark the lenses with a pen? This step is called PD measurement.

For anyone who is not familiar with PD, what it means, and why it is important for an eye exam and prescription glasses, Monde Eyewear has put together the essential information you should know.

What Is PD and Why Is It Important?

PD, or Pupillary Distance, is the distance between the centers of your two pupils, measured in millimeters. This value is very important when making prescription glasses because it helps the optical technician position the lenses correctly and align them with your eyes. This allows the wearer to enjoy glasses that perform effectively, feel comfortable, provide clear vision, and help reduce eye strain.

PD measurement is especially important for people with complex prescriptions, high prescriptions, or those who need progressive lenses.

What Happens If PD is Not Measured or Is Incorrect?

Whenever you get new prescription glasses, PD is an important value that should not be overlooked. Think of PD as the coordinates that indicate the position of your eyes, helping ensure that the lenses are made to align properly with your pupils. If glasses are made without measuring PD, or if the PD measurement is significantly inaccurate, it can affect how the glasses perform.

Possible issues include:

The lenses may not align with the center of the pupils, causing vision to be less sharp than it should be.
You may experience eye discomfort, eye fatigue, or feel like you need to strain your eyes more than usual.
Eye pain or headaches may occur because the eyes need to work harder to focus.
In some cases, incorrect PD can cause double vision, especially when looking at distant objects.

At Monde Eyewear, you do not need to worry about PD measurement. We offer a free 16-step BVAX standard eye examination, conducted by experienced staff who carefully check your vision through every step. This helps ensure accurate vision measurement and glasses that feel as comfortable as possible.

Looking for an optical store near you? Discover quality prescription eyewear stores with branches across Thailand. Read more here: Prescription Glasses Store Near Me

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