What is a PD for Eyeglasses?
When buying eyeglasses, you might hear the term PD thrown around. But what does it mean, and why is it important? In this article, we’ll dive into what PD is, the difference between single and double PD, how to measure it, and why optometrists use terms like OD and OS in your prescription.
1. What is Pupillary Distance (PD)?
Pupillary Distance (PD) is the measurement between the centers of your pupils. It’s crucial to ensure the lenses in your eyeglasses that align perfectly with your eyes for clear vision and reduced strain. A wrong PD can lead to discomfort or blurry vision.
Why is PD important?
● It determines where the optical center of the lenses should be placed.
● Helps create lenses tailored to your specific vision needs.
2. Single PD vs. Double PD
Single PD
It is the measurement in millimeters that shows the distance between the centers of your pupils. It’s commonly used for single-vision lenses.
Double PD
Double PD provides two separate measurements:
● Distance PD: For seeing far.
● Near PD: For tasks like reading or using a computer.This is typically needed for multifocal or progressive lenses.
3. How to Measure Pupillary Distance?
You don’t need to visit an optometrist to measure your PD, you can do it yourself or get help from a friend. It explains the specific methods below.
Measure Your Own PD
1. Stand about 8-10 inches away from a mirror.
2. Hold a ruler against your eyebrows.
3. Close your right eye and align the ruler’s zero mark with the center of your left pupil.
4. Without moving the ruler, close your left eye and open your right eye. Note the measurement at the center of your right pupil.
5. Repeat to ensure accuracy.
Measure a Friend’s PD
1. Ask your friend to look straight ahead.
2. Hold a ruler against their eyebrows.
3. Measure the distance between the centers of their pupils.
Tip: Some online tools and apps can help calculate your PD too!
4. Optometry Terms: What Do OD and OS Mean?
When looking at your eyeglasses prescription, you may notice the terms OD and OS. These are abbreviations used by optometrists:
● OD (Oculus Dexter): Refers to the right eye.
● OS (Oculus Sinister): Refers to the left eye.
In some prescriptions, you might also see OU, which stands for both eyes. These terms help the optometrist provide the correct lens power for each eye.
Quick PD Reference Table
Final Thoughts
Understanding your pupillary distance (PD) and your prescription details are the keys to getting eyeglasses that are comfortable and effective. Whether measuring your own PD or working with your optometrist, having the right information ensures your eyewear fits your needs perfectly.
At Zeelool, we’re committed to making eyewear shopping easy and enjoyable, helping you see the world with clarity and style!
About ZEELOOL
ZEELOOL is a leading online retailer specializing in affordable and fashionable eyewear. Established in 2017, with a diverse selection of glasses, including women's glasses, men's glasses, reading glasses, and kids' glasses, it is not merely your perfect fashion accessory but also a medium for interpreting your life attitude and style, an expression of a unique perspective on the world. Committed to customer satisfaction and innovation, ZEELOOL continually updates its collections to reflect the latest trends and fashion statements.
