What Is & How To Obtain Your Pupillary Distance?

What Is My Pupillary Distance?

What is Pupillary Distance (PD)?

Your Pupillary Distance is the distance between the centre of one pupil to the centre of the other pupil (the blacks of your eyes) measured in millimetres.

It is usually written as one value (e.g. 66mm) but sometimes written as two values.

We encourage you to ask your optician for your PD measurement. However, if you do not have a PD value on your prescription do not worry, you can measure it manually or by using our high-precision online tool (available for customers ordering Varifocals).

How to measure your Pupillary Distance (PD)?

Method 1

Measure your PD manually

The pupillary distance can be easily measured by looking in a mirror and using a ruler! Please follow these steps:

- Stand in front of a mirror at a distance of about 20cm (8 inches)

- Close your right eye

- Place your ruler flat against the mirror and align it horizontally with the millimetre scale pointing upwards

- Looking over the top of the ruler with your left eye, align the zero mark of the ruler in the centre of your left pupil

- Now open your right eye and close your left but keep your head still and the ruler in the same position

- Read the millimetre measurement corresponding to the centre of your right pupil

To be sure, you can repeat this process a few times for consistency

We can send you a custom-made PD ruler to help you measure your PD if this is helpful.

Method 2

Measure your PD online (Available for customers ordering Varifocals)

Simply visit our online tool (you need to be logged in) on a device that has a webcam/camera. You can use your phone, tablet or your computer. When you load the tool, it will run you through some basic instructions, and with a quick image, you will receive your PD measurement accurate to 0.5 mm.

You can then supply us with this value via email (or our online prescription form) if we require it to make up your glasses.

When Do I Need a Pupillary Distance (PD) Measurement?

A pupillary distance (PD) measurement is only essential when you're ordering varifocal lenses.

Varifocals have multiple focal points for distance, intermediate, and near vision, which means that the lenses need to be perfectly aligned with your pupils to work effectively. Without an accurate PD measurement, the different sections of the lens might not align correctly, leading to blurred vision or discomfort.

Having the right PD ensures smooth transitions between the different zones, providing clearer and more comfortable vision across all distances.

For single-vision and bifocal lenses, an exact PD measurement is less important. Single-vision lenses focus on one distance (either far or near), so an average PD is enough to offer clear vision. Similarly, bifocal lenses, which have two focal points, don’t require the same level of precision as varifocals.

Why is PD Important For Varifocal Lenses?

Pupillary Distance (PD) is important for several reasons to ensure your glasses perform correctly, are comfortable, and fit well. Here’s why PD is crucial:

Optimal Vision Alignment: Properly aligned lenses ensure that your vision is clear and sharp. An incorrect PD can misalign the lenses, leading to blurry vision and discomfort. Accurate PD ensures that the optical centre of the lenses sits directly in front of your pupils for the best visual clarity.
Enhanced Comfort: Glasses that don’t match your PD can cause eye strain, headaches, and fatigue. By ensuring your lenses are perfectly aligned, you reduce the risk of these issues, making your glasses more comfortable to wear throughout the day.
Perfect Aesthetic Fit: A correct PD measurement also contributes to the overall fit and appearance of your glasses. It helps position the lenses in the frame in a way that looks natural and feels comfortable, enhancing both functionality and style.

I Have My PD, What Next?

Once you have your Pupillary Distance (PD) measurement, you're ready to find your perfect varifocal glasses. By using your unique PD, your new varifocals will ensure you experience perfect vision that is both clear and comfortable.

Here’s what to do when you have measured your PD:

Choose Your Frames: Browse our wide range of frames and select the ones that best suit your style and needs. Remember to consider the size and shape that complement your face. You can visit our “Glasses to Suit Your Face Shape Guide” for help with finding the right glasses for you.
Customise Your Lenses: We have a range of lens styles available, but a PD measurement is only 100% necessary when choosing varifocal lenses. After you have selected your lens type, you will be able to add additional features like anti-reflective and anti-scratch coatings or blue light blocking and UV-blocking filters.
Provide Your Prescription: During the checkout process, you’ll have the option to enter your prescription details, including your PD. Make sure to input the PD measurement accurately to ensure your lenses are perfectly suited to your specific visual requirements.

Measuring Your PD FAQs

What happens if I measure my PD incorrectly?

If your PD is incorrect, your lenses may not align properly with your pupils, which can cause discomfort or blurry vision. It’s essential to measure it accurately to ensure your glasses provide optimal clarity.

Can I use an average PD if I don’t have my exact measurement?

While it’s possible to use an average PD, it’s not recommended for precise vision correction. The average PD is around 63mm, but individual measurements can vary significantly. For the best results, use your exact PD.

What if I don't have my PD on my prescription?

You only require a PD measurement if you are ordering varifocal lenses. You can either measure it manually or use our online tool. Alternatively, you can ask your optician to provide your PD during your next visit.

Why is PD important for varifocal lenses?

PD is crucial for varifocal lenses because it ensures that the different lens zones (distance, intermediate, and near) are aligned correctly with your eyes. This alignment is key to the lenses functioning properly and providing clear vision at all distances.

How do I update my order if I measured my PD after placing the order?

If you’ve already placed an order but measured your PD later, contact our customer service team as soon as possible. They can help update your prescription details before your lenses are made.