How to Measure Your Pupillary Distance(PD)

What is the pupillary distance?

The pupillary distance is the distance between the pupils, the two eyes are looking straight ahead, and the distance between the two pupils is the pupillary distance, in mm.

The average PD for adults is between 54-74 mm; for children, it is between 43-58 mm.

Why Measure the Pupillary Distance?

Pupillary distance has a lot to do with our comfort level when wearing glasses. pupillary distance must also be provided when filling out the prescription form on the website.


The pupil distance between the eyes should be basically the same as the distance between the center of the lens, and the image is clear.

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There is a deviation between the pupil distance of the eyes and the distance between the center of the lens.If the pupil distance is small, wearing large-frame glasses will cause the focus of the pupil and the lens center to deviate.

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How to Measure Pupillary Distance?

Usually your optometry sheet will have a pupillary distance value. What if you don't know the pupillary distance value?


Measure yourself
First you need a ruler and a mirror.

Step 1
Stand straight facing the mirror and align your face horizontally with the center of the mirror.
Step 2↓
Place the ruler horizontally above the eyebrows, parallel to the eyebrows, and the distance between the two pupils is your pupillary distance.

If your friend helps you measure the pupillary distance

1. Please open your eyes, keep your sight straight and don’t deflect your head.
2. Ask your friend to place the 0 scale above the center of one of your pupils, and then read the distance to the center of the other pupil.