Pupillary Distance (PD) is the measurement of the distance from the center of one pupil to the other. It is a simple but crucial measurement when shopping for glasses online because it’s the method used to ensure that the lens’s optical center is properly positioned over the pupil.

There are instances where people’s eyes are not perfectly symmetrical. In such cases, people measure the distance from the bridge of the nose to the center of each eye. This method, referred to as dual pupillary distance (DPD), typically results in a better fitting lens because each eye has been measured accurately, despite the lack of symmetry.

There are several ways to measure this distance at home. Technology is available that can figure out the distance with a card with a magnetic strip and a webcam. You could also measure PD with your Smartphone or with a ruler. Still another way, if you’re in a pinch, is to use an old pair of glasses.

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How to Measure Pupillary Distance Using Old Glasses

  1. Put your glasses on and stand 8 to 10 inches away from a mirror.

  1. While staring straight ahead, use a non-permanent marker to mark where the center of your pupils lines up with your glasses. Good potential choices for your non-permanent marker would be a washable or dry erase marker, or a highlighter. Keep those pesky sharpies away from your lenses so they can’t do any permanent damage.

  1. At this point, you’re ready to measure the distance between the dots, at which point, you’ll have your PD measurement.

  1. Just to repeat, this is the least accurate method of determining your PD measurement. A way to add a bit more accuracy is to have somebody else make the marks for you. Just make sure they have the right non-permanent marker in their hand.


What if the PD Is Not Measured Correctly?

If the Pd is not measured correctly and lined up to the exact center of your pupils, your vision will be affected in a negative way. It will feel as though you’re wearing someone else’s glasses. A mismeasurement can lead to headaches, blurry vision, fatigue and eye strain.

What Is the Average PD Measurement?

The PD for most adults is between 52-72mm. Most males end up on the higher end (56-72mm) while most women end up on the lower end (52-64mm). The average PD for men is 64mm, while the average PD for women is 62mm.

Does Your PD Measurement Ever Change?

Your PD does change as you grow from a child into an adult but it is extremely unlikely that there would be further changes after puberty. This can work in your favor, though, as once you get the correct measurement once, as an adult, you’ll never have to take the PD measurement again.

How Accurate Are PD Measurements?

When performed by an optometrist, PD measurements are almost always perfectly accurate. If you do your own, at home, you do not have to be 100 percent accurate. Though it can tolerate a small error range, it is recommended that you attempt several measurements to ensure accuracy.

What if Your PD Is Too Small for Your Frame?

Now that you know what is pupillary distance, you might ask about the frame of the glasses. Experts expect the pupils to sit slightly closer to the inside of the frame than the outside, but close to the center of the lens. If you have a PD of 40, you will need a frame with a smaller PD and if you were to try on frames with a PD of, say, 60, your vision would be affected as though you were cross-eyed.

PD measurements ensure that your vision remains clear and there are several ways to make sure that they’re done correctly, even if you’re at home, purchasing prescription glasses online. Visit the Marvel Optics website today and check out their current inventory of sunglasses so that your precious eyes will be protected tomorrow.

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Best Prescription Glasses

WileyX Profile

WileyX Profile

The WileyX WorkSight series of frames includes prescription-ready safety glasses. The Profile style has rectangular frames with full rims. Triloid frames and polycarbonate lenses meet the American National Standards Institute Z87.1-2010 high velocity and mass impact requirements and U.S. federal Occupational Safety and Health Administration 1910.133(b)(1)(1) standards. These glasses come with a fold-over case, removable side shields and a drawstring storage pouch.

Profile frames may be available in several color choices such as Gloss Brown Demi, Gloss Green Demi, Matte Hickory Brown, and Matte Black. This eyewear can accommodate single vision, bifocal and progressive lenses. Check the frame size and dimensions to determine whether Wiley X Profile can provide the best fit for daily, occupational or activewear.

ArmourX 6001

ArmourX 6001

Another popular frame style ready for prescription lenses is ArmourX 6001. These plastic glasses with polycarbonate lenses meet ANSI Z87.1 safety standards. Large black rectangle frames wrap around the wearer’s face. While these glasses are compatible with single vision, bifocal or progressive lenses, the base curve may not be the best choice for high Rx lenses.

The 6001 style frames from ArmourX are suitable for on-the-job or activewear. A lightweight frame design is paired with lenses treated to resist dust, fog, reflections and scratches. When fitted with clear or tinted lenses, this eyewear provides protection from ultraviolet rays. This style is popular because it is comfortable and stylish enough to wear inside and outside while doing a wide range of activities.



A double bridge distinguishes Shellshore by Marvel Optics apart from other metal rectangular frames. This small feature draws attention upward toward the browline, which can be helpful for balancing the features of a round, oval, triangle or diamond-shaped face and adding an element of style. These full-rim glasses come in a small size and accommodate single vision lenses.

Rectangle-shaped frames with a double bridge are ideal for oval and oblong face shapes. Check the measurements of these frames to determine whether Shellshore is the right safety prescription glasses style for you. These frames may be available in colors such as blue, gunmetal or jet black.

M-Line Brave

M-Line Brave

Brave frames by M-Line have on-trend vintage styling at an affordable price. These round acetate full-rim glasses have spring hinges. Some versions combine black frame fronts and colored temples. Single vision, bifocal and progressive lenses can all be fitted into these frames, as can high Rx prescriptions. An anti-scratch coating maintains optical clarity for comfortable wear and value.

Check the dimensions of Brave frames to determine whether this style is the best choice for your face. Men and women can both sport this retro style. Choose from several shades such as matte black with navy temples, matte black with red temples and matte black. You can also customize this style with clear or tinted lenses.



One of the most popular prescription frame styles for women is Katelyn by Marvel Optics. These cat-eye full-rim frames are another vintage style updated for modern wear. Plastic frame fronts and temples feature textural details for a unique look. The best online prescription glasses for women are compatible with single vision, bifocal, progressive lenses and high Rx prescriptions.

If you have an oval or pear-shaped face, you may want to consider Katelyn frames. These glasses can be fitted with clear or tinted lenses with an anti-scratch coating for vision correction or sun protection. These glasses come in a medium size. Check the dimensions of this eyewear to determine whether it will provide the best fit. Marvel Optics makes more prescription-ready styles for women.