What Is PD?
PD, an abbreviation of pupillary distance, also referred to as pupil distance, is the distance between the center of each pupil and the bridge of your nose measured in millimeters. Pupillary distance is very important for making prescription glasses because it is used to determine where you look through the lens of your glasses, so it should be as accurate as possible.
If the pupillary distance is not accurate, the prescription power of your lenses will be off-center from your eyes and you won’t be able to see clearly from your glasses.
The average adult’s PD is between 54-74 mm, and the average kid’s PD is between 43-58 mm.
PD is measured in millimeters in one of two ways, from each pupil individually or together between the center of both pupils. So, what is single PD, and what is dual PD?
What Is Single PD?
The single PD, also called binocular PD, is the total distance between the middle of both your pupils added together.
What Is Dual PD?
Dual PD, also called monocular PD, is the measurement of the center of each pupil to the bridge of your nose individually.
Single PD vs Dual PD: What Are the Differences?
As for single PD vs dual PD, you have learned some differences. So, is it better to have a single or dual PD when purchasing a pair of new glasses? Is one more accurate than the other?
Our eyes are not equally proportioned or symmetrical. One pupil could be a little further away from the bridge of your nose than the other pupil. Due to this, a dual PD is usually recommended. When you have each pupil-to-nose bridge measured individually, you will be sure to get your prescription right where you need them to be on your lenses, especially when you are considering progressive lenses or bifocal glasses.
All in all, PD is very important when you want to get a pair of prescription glasses. So, make sure of its accuracy.
As for single vs dual PD, this post from Koalaeye Optical has shown their differences. If you have any different ideas for single PD and dual PD, share them in the comment zone. If you have any problems with glasses or sunglasses, do not hesitate to contact us via the email service@koalaeye.com and we will reply to you as soon as possible.
