Single PD is the total distance between the center of both pupils. We recommend measuring dual PD. This is why: Dual PD is believed to be the most accurate since many people have different distances between their nose and pupil on each eye.
What is the difference between single PD and dual PD?
Single Vs Dual PD Dual PD is the measurement of the center of each pupil to the bridge of the nose. Single PD is the total distance between the center of both pupils.
What happens if you have 2 PD numbers?
If your PD has two numbers, do not worry, as it is very simple to figure out. If the two numbers are the same, add them together to get your PD number. If the two numbers are different, the higher number of for distance and the lower number is for near vision.2021-01-07
How do I know if I have single or dual PD?
A single PD would be provided by one number and is the measurement of the center of one pupil to the center of the other. ... A dual PD would be provided with two numbers and would appear and is the measurement of each pupil center to the center of the bridge of the nose, in millimeters.
Is PD important for single vision glasses?
Pupillary distance is extremely important when fitting any kind of glasses – including single vision glasses. ... Glasses lenses are designed that way for maximum effect. If the measurement is not correct, this optical centre will still be at the centre of the lens, but it won't align with your pupil.2018-05-20
What is a normal single PD?
The average PD measurements for women is 62mm and for men 64mm. Between 58 and 68 is quite normal though. ... We do encourage you to ask your optician for your PD measurement.
Can you have 2 pupillary distance?
Typically, there will only be one number in your PD measurement - this is called Single PD, and it can be used to order most types of prescription eyeglasses. But if you have two different numbers, you have been measured for Dual PD (also known as monocular PD).
Why do I have 2 different PD numbers?
Your Numbers The first number, which is always higher, is for distance, and the second number, which is always lower, is for near-vision reading only. Another example is if your numbers are 34.5/33.5, then it means your PD was taken one eye at a time.2015-05-25
Can PD be different?
Typically, adult pupillary distances range between 54 to 68 mm and children range from 41 to 55 mm. During the day, your PD can vary about 3-4 mm depending on your viewing distance. ... Your PD automatically adjusts during the day, as your eyes move between different viewing distances.2018-10-23
Is dual PD better?
Although both single and dual PD can be helpful for determining lens fit and size, dual PD is perhaps considered the more accurate of the two. This is because single PD simply measures the distance between both pupils, while dual PD measures the two distances from the bridge of the nose to the pupil of each eye.