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Does Your Pupillary Distance Change Over Time?

Updated: Feb 3

Does your pupillary distance change over time? And why does your pupillary distance matter in the grand scheme of things? If you rely on glasses to correct your vision, your pupillary distance is essential to getting properly fitted for glasses. A miscalculation by even a tiny fraction can completely change your ability to see.

If you want to get the most out of your glasses, determining your pupillary distance is key. That’s why in this article, we’re going to explain what pupillary distance is, why it matters, and how to determine pupillary distance for your prescription glasses.

What Is Pupillary Distance (PD) & Why Does It Matter?

So what is pupillary distance and why is it important for your eyewear? Pupillary distance is the measurement of distance between the centre of your pupils measured in millimetres. It’s an essential step in determining the proper lens cut and frame for your glasses.

If you’ve ever needed prescription glasses before, your optometrist likely measured your pupillary distance and wrote this down on your prescription using the abbreviation “PD”. Your pupillary distance is used to precisely measure where the optical centre of your lenses should be. If this measurement is incorrect, your pupils won’t align with the optical centre of the lenses, throwing your vision off.

An incorrect measurement of pupillary distance can lead to the inability to focus, headaches, blurry vision, strained eyes, nausea, and dizziness. That’s why our stylish reading glasses come with the exact prescription power that you need.

How Is PD Measured?

You may be wondering how to determine pupillary distance. In order to get an accurate measure of your pupillary distance, we recommend visiting your optometrist. They will use a corneal reflex pupillometer to measure your pupillary distance accurately and efficiently.

Visiting your optometrist for an accurate measurement is always better than buying over-the-counter glasses. Although they are convenient, over-the-counter glasses won’t be fitted to the pupillary distance that you have.

Can I Measure My Own Pupillary Distance?

Yes, you can measure your pupillary distance at home. All you need is a millimetre ruler and some patience. To get an accurate measurement, we recommend measuring yourself multiple times. Remember, even a slight miscalculation can reduce the effectiveness of your reading glasses.

To begin, grab a millimetre ruler and stand in front of your mirror. Place the ruler flat against the mirror, then close your right eye. Try to align the beginning marker of your ruler with the centre of your pupil in your left eye. Follow the same procedure for your right eye without moving the ruler. Write down your measurements.

We suggest repeating this process several times to get the most accurate reading possible. Compare the measurements, then calculate the mean number to most accurately determine your pupillary distance.

How Accurate Does Pupil Distance Need To Be?

Now that we’ve covered how to measure pupillary distance, how accurate does pupil distance need to be? If you get measured by your optometrist, you will be receiving the most accurate pupillary distance measurement possible. You may receive a prescription with one PD value or two PD values, depending on your eyesight.

These pupillary distance measurements determine the best placement of the optical centre of your lenses, through which your vision will be corrected. The more accurate your PD measurement, the better your glasses will perform and the better your vision will be. That’s why it’s important to get an accurate pupillary distance measurement.

The higher prescription power you need, the more important it is that your measurement is accurate. If your prescription is for low myopia (known as nearsightedness), an inaccurate pupillary distance measurement won’t impact your vision as much. However, if you have high myopia, an inaccurate measurement can lead to headaches, amongst other symptoms.

That’s why we always recommend seeing a professional optical practitioner to ensure you get the perfect prescription glasses for you.

Single Pupillary Distance vs. Dual PD

If both of your eyes have the same pupillary distance, you will need single vision glasses. Single vision glasses can correct myopia or hyperopia with the same prescription power in both lenses. On the contrary, dual vision glasses can correct vision problems in one or both eyes, depending on your needs.

Does Pupillary Distance Change Over Time?

Now you may be wondering, does pupillary distance change over time? Yes, even if you get an accurate measurement of your pupillary distance, it may change in the future. This all depends on your age. Your pupillary distance can change in your childhood and adolescence, but once you reach adulthood, it will most likely remain the same throughout your life.

That’s because your skull can physically change as you grow, meaning your pupillary distance won’t stabilize until adulthood. A child’s pupillary distance is typically 10 to 30 millimetres less than an adult’s. The average pupillary distance for adults is between 50 to 70 millimetres, give or take. Adult males will typically measure 70mm, while adult females can fall between 50 to 65mm.

Using Your PD To Find The Perfect Frames

Once you have an accurate measurement of your pupillary distance, you can freely order glasses online without the hassle of looking in-store. At Pat & Jack, we make affordable and stylish reading glasses with any prescription power. Our reading glasses are designed to protect your vision with water repellant, scratch resistant, and blue light filter lenses, perfect for reading or working online.

Order magnetic, classic, and vintage style glasses today, specially designed in Montreal and delivered to your doorstep.

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