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What Is Pupillary Distance?

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Pupillary distance is the distance measured between your right and left pupil. Your measurements depend on what you see at what distance. This measurement is very important for people who have to wear eyeglasses. The measurement has to be accurate so that you see properly with your glasses and use them for activities such as reading, writing, or watching a movie.

There are two types of measurements for pupillary distance. One is Monocular PD, in which the distance is measured from the nose to both the right and left pupil. These measurements usually consist of two numbers. The other one is called Binocular PD, which is the total distance between both your pupils. Binocular measurement is commonly most used to take PD measurements. This method is used mostly for people who are getting eyeglasses made.

For people who wear lenses the pupillary distance has to be perfectly measured for clear vision.

A child’s pupillary distance ranges mostly between 43mm and 54mm. On the other hand, an adult’s pupillary distance lies between 54mm and 74mm. Professionals write these measurements into two figures, but they can write only one as well.

Your pupillary distance can also vary according to your age, sex, and race.

How to Measure Your Pupillary Distance?

There are different ways to get your pupillary distance measured. Mentioned below are the following ways to measure your pupillary distance:

  1. Mostly the measurement takes place while you’re getting your eyes tested by an optician. Opticians use a particular machine called a corneal reflex pupillometer, or some of them measure it by using a ruler called a PD stick.
  2. You can also measure your pupillary distance with the help of another person. This is done by making the other person place a ruler on your nose. If you’re doing it by yourself, measure to stand about eight inches away from the mirror and try not to move too much. Make sure the starting point of the ruler is in the middle of your nose. Mark the center of the right eye on the ruler. Your pupillary distance is the distance between your starting and ending point.
  3. There are different applications and software that help you measure your pupillary distance. This is done with the help of your phone.

It is also important to read the measurement correctly. Even the slightest misread can cause you difficulty in seeing through your glasses. This worsens your eyesight as the number of each pupil starts to increase. Make sure to always get an accurate measurement of your pupillary distance, especially before getting new glasses. Or if you feel like you cannot see properly or you’re putting too much strain, visit an eye doctor because you might need glasses!

Written by Total Focus

At Total Focus Optometry, we’ve spent the last 70 years building meaningful relationships with our patients and their families. From routine eye exams to contact lens fittings we offer our patients a variety of services to meet their eye care needs.

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