PUPILLARY DISTANCE HOW TO TAKE THE MEASUREMENT
(Also referred to as “Pupil Distance” or “PD”).
If you’ve never ordered prescription eyeglasses online before, the first time might be a little scary, especially if you see words like “pupillary distance” that you don’t know. Don’t worry, we’ll take care of you. This article will tell you everything you need to know about pupillary distance, how it affects your prescription, and how to measure it.
What exactly is PD?
Pupillary distance, often known as pupil distance or simply PD, is the measurement in millimeters between the center of each pupil and the bridge of your nose. Pupillary distance is important when making prescription glasses because it tells us where to position the center of your vision on your lenses. Even if your prescription is 100% right, you won’t be able to see out of your glasses if you don’t get the right measurement.
How can I determine my pupillary distance?
There are two options:
You can get it from your eye doctor.
You probably didn’t know this, but every pair of glasses you’ve ever bought from an optician had their lenses custom-made based on your PD measurement. The prescription you obtain following an eye exam may or may not contain this measurement. Ask an optometrist for your PD or take a self-measurement if you wish to buy glasses online. If getting your measurement from your eye doctor isn’t an option.
Can I just estimate my PD?
Do not order glasses without first having your pupillary distance measured.
A correct measurement of the interpupillary distance is essential for the effective use of eyeglasses. It’s like ordering a pair of shoes online without knowing your exact foot size and then having to return them because they’re either too large or too tiny. For the same reason, if you estimate your pupillary distance, your prescription glasses won’t focus correctly and you’ll have to get a new set.
What is the difference between single and dual PD?
They are not scientific terms for:
Sometimes called “dual PD,” monocular PD is the distance from the center of one pupil to the bridge of the other eye.
The entire distance between the centers of each pupils is known as binocular PD (or simply PD).
How long is the typical pupillary distance?
A binocular PD of 50mm or less is considered normal for a youngster. If you receive such figures, we suggest that you double-check your ruler and methodology before measuring again!
My PD is 32, and the range of PDs for the frame is from 58?
If your doctor records your PD as being less than 40, it is likely that you have monovision. If just one number is given, multiply it by two to get a range that corresponds to the frame’s PD. When placing your order, choose “Monocular PD” as your prescription type.
Method #1: How to Find Your PD with the help of a Friend
If you want to measure your pupillary distance (pd) at home, the best way is with the help of friend. You will need a friend and our special ruler for this. (NOTE: If you can’t find a friend you will use method #2 farther down).
- Print out our tip sheet, which has a special ruler to help you figure out your PD. Make sure it’s the right size by putting your driver’s license next to the key.
- Ask your friend to stand at least 8 inches away. Hold the special ruler so that the middle is right in the middle of your nose bridge.
- Look straight ahead and close your left eye to measure your right eye. Your friend should close their right eye and look at the mm mark right above the center of your right pupil on the ruler.
- Close your right eye and look straight ahead to measure your left eye. Then, your friend should close their left eye and look at the mm mark right above the center of your left pupil on the ruler.
- To achieve an exact measurement, repeat this method at least three times.
Method #2: How to find your own PD
You will need a mirror and our special ruler to measure your own. (NOTE: The best way to measure is with a friend. Scroll up to Method #1 to see our guide for this.)
- Print out our tip sheet, which has a special ruler to help you figure out your PD. Make sure it’s the right size by putting your driver’s license next to the key.
- Stand about 8 inches or further away from a mirror. Hold the special ruler so that the middle is right in the middle of your nose bridge.
- To measure your right eye, look straight ahead while closing your left eye, and note the mm mark just above the center of your right pupil on the ruler.
- To measure your left eye, shut your right eye and look straight ahead, noting the mm mark on the ruler just above the center of your left pupil.
- To achieve an exact measurement, repeat this method at least three times.
FYI: Your total pd is the addition of your right eye measurement and left eye measurement.
