How to Measure Your PD (Pupillary Distance) with SelectSpecs (HD)


The Pd or pupillary distance is the [distance] between the center of your pupils measured in millimeters. This measurement ensures your prescription lenses are correctly centered in front of your eyes when purchasing new glasses This measurement is especially important for people with higher prescriptions Your pD is not always given as part of the prescription when you have an eye exam You should ask your optician for the PD measurement However the optician testing your eyes is under no obligation to provide it or there may be a small fee Thankfully you can measure your pD yourself with the help of a friend or a family member There are two types of PD Measurement. One for distance and one for reading The distance PD measurement is used for distance intermediate bifocal or very focal glasses The reading PD measurement will be used only for reading glasses We will show you how to measure both types of PD measurement in this video The selectspecs PD rule is designed to fit over the bridge of your nose with sections cut out for your eyes to look through With the help of another person sit opposite each other about an arm’s distance apart your helper should hold the PD Ruler between their thumb and forefinger resting the ruler on the bridge of your nose and Steadying their hand by placing the remaining fingers against your head The person taking the measurement should close their right eye and look directly opposite into your right eye Make sure you look directly into their open eye as you are being measured Make a mental note of the measurement from the bridge of the nose to the center of the pupil in millimeters Without moving the PD rule the person taking the measurement should close their left eye and use their open right eye To look into your left eye directly opposite Again make sure you look directly into their open eye as you are being measured Make a mental note of the second measurement from the bridge of the nose to the center of the pupil in millimeters Now add these two numbers together to get your PD measurement Repeat the process several times until you are happy with the accuracy of your results in general an adult Pd measurement or for somewhere between 55 and 72 millimeters If you don’t have a pd ruler you can use a standard Ruler with millimetre measurements Taking the same positions with your helper as before the person taking the measurement should close their right eye Using their open left eye They look directly into your right eye opposite lining up the zero on the ruler with the center of your pupil Make sure you are looking directly ahead into their open eye as you are being measured The person taking the measurement should rest the ruler firmly against your forehead to keep it steady Without moving the Ruler the person taking the measurement should close their left eye and use their open right eye to look into your left eye directly opposite Again make sure you look directly into their open eye as you are being measured The measurement at the center of the second Pupil is your PD measurement Repeat this process several times until you are happy with the accuracy of your results Remember to keep your head perfectly still as you are being measured If you are purchasing reading glasses, you’ll need your reading or near PD measurement The principle for measuring a reading PD is almost identical to measuring a normal distance PD The person taking the measurement can simply follow the instructions already mentioned in this video The only difference is that the person being measured should focus on an object closer to their face. Hold a pen around 30 centimeters in front of your face and keep your focus here while your pd is being measured. This will cause your eyes to converge slightly giving you a more accurate reading PD measurement We advise Against measuring your PD yourself using a mirror because the distance to the mirror surface and your reflection in the mirror can vary dramatically while taking the measurement which may result in a less accurate PD measurement If you are not comfortable or confident enough to measure your pD with some help it is possible to take your measurement from an existing pair of glasses When placing an order for new glasses you can choose to send your old glasses to us and we can take the measurement from those. The glasses must include both prescription lenses for a measurement to be possible Once a PD measurement has been taken from your old glasses we can even return them or donate them to charity if you no longer need them Once you know your PD measurement. You should write it down and keep it with your prescription in a safe place Unlike your prescription the PD measurement won’t change over time

Comments 67

  • Thaks! Excellent information to measure PD.

  • This is the only accurate information on measuring a PD that came up on page one of my Google search. I'm an Optician who was curious to see if online orders were giving accurate info for measurements. Well done!

  • Many thanks for your kind comment. It means a lot coming from someone like you.

  • What a totally brilliant video, so helpful. I rang my opticians enquiring about my pd reading only to be informed that I would have to pay £40 for this privilege. Money for jam or what?!!!!!!!!!.

  • Happy to be of service.

  • yes, this will be ok
    🙂

  • A few days ago, I slightly modified the online instructions I found and used a pair of digital vernier calipers. When I stared up at a smoke detector in the ceiling with my head tilted, my daughter took my PD, then I had my spouse to it, and we arrived at 63. I had unreliable results going from the bridge of the nose however. Now that I have seen this I will do it again and get another measurement for the readers Rx. I read somewhere that you can have a margin for error of 1.5 on your PD? Thanks

  • It depends on how strong your prescription is really.
    If you only have a small RX, you can usually get away with a slight difference, but you should always try to be as accurate as possible. Take the reading several times to be sure and if in doubt, you can always get a second opinion from someone else.

  • Thanks for the feedback. I also found a blog post about using dots on your existing lenses and as I was alone at the time I tired it. It made a difference on the readers by a factor of 3mm. Next when my spouse is around to help I will try your method and hope that they correlate so I can have some confidence. While looking around I noticed that even some optometrist forums have varying opinions as to which methods that they use are best and that even they can have different results.

  • If it makes you feel more comfortable, you can always choose to send your old glasses to us when you place your new order – we can take your PD from an old pair of specs – as long as it has both lenses and the frame is not snapped in half 😉

  • Thanks for that, when my spouse went for an eye exam today we managed to charm the receptionist into giving us our PD's for free. Distance was same as what I had measured, but the readers were off by about 1.5 in my case and different for each side (29/30.5). This should facilitate future online purchases. In the case of my spouse we used the method here before she went and it matched within .5.

  • I am totally shocked! I just bought a pair of binoculars (Celestron 20×80) and I can barely see thru them (with both eyes at the same time). The reason? I have a interpupillary distance of 83~84mm! I was doing some research and I cannot find any person with this scale. There is a study performed by Neil A. Dodgson, from Cambridge University called "Variation and extrema of human interpupillary distance" that you can find as a link in Wikipedia in the article "Pupillary distance" (continues)…

  • (from last comment) …but the scales used in the article stops at 80mm. Does anybody know of cases like my own? I am totally out of scale and I would like to know more about this extreme cases. Any information will be appreciated. Thank you.

  • Hi,
    If you were planning to order some glasses from us, you should select a PD of 80 but be sure to leave a comment/note with your order to amend to 83.
    It does seem large, and considering it is so far from the average we would recommend you probably try to get your measurement confirmed at an opticians before ordering.

  • Thanks for your answer, indeed I will confirm my measurement with an expert before doing anything else. Thanks again.

  • Opticians go to school to learn to measure PDs, its not really something you can learn from a video.

  • With all due respect, measuring a PD is pretty much the first thing you learn, within the first week, or even first day of your optical training.
    Ideally, opticians should give patients all the information they need, but if not, we believe our video shows people clearly how to go about measuring a PD if they need to.
    If people are not comfortable measuring a PD themselves they can send us an old pair of glasses and we can measure their PD from those.

  • Using a mirror to measure your PD isn't difficult. You just halve the distances. Instead of thinking of the mirror itself as the focal point, think of the reflection as another person and position that person the correct distance away.

  • I just order glasses online and I was confused what a pd was. So i guessed and choose 62. Now I found out my pd and it is 63 just 1 mm off but I dont think it will effect my glasses.

  • IF I SEND MY OLD GLASSES TO GET THE MEASUREMENTS WILL YOU GUYS SEND THEM BACK.

  • My eye prescription is -4.50 on both eyes, does it matter If im 1mm pd off?

  • Excellent, clear instructions.  Thank you very much.

  • Excellent.
    To recap my pd measurement will not change?
    What are the chances my pd will change? Thanks

  • mine is 72 mm 

  • Hi everyone,
      I'm wondering how would you measure far pd for each eye and near pd for each eye. And would you be able to do that on a lens as well? thanks

  • Ask your optician for your PD measurement. If they refuse to give it to you, tell them The Freedom of Information Act clearly states it is an offence for any organisation holding personal information on a person, not to give that information to them if requested. If they still refuse, report them to Trading Standards and then go round to the local court and sue them for it. They will end up paying all the costs.

  • Eye-net Ltd. are thieves and crooks, do not trust them with your money. They are a rip off company.
    Eye -net Ltd. sind Diebe und Gauner , nicht mit Ihrem Geld traue ihnen . Sie sind eine Abzocke Unternehmen .

  • This is hilarious. Have fun trying not to move your eyes to get the exact PD needed for glasses. Have fun accidentally making yourself cross-eyed.

  • ahhhh i always forget how to do it!

  • 2:07 gets me every time.

  • You say to "close your right eye and look directly into your friend's right eye", but in the video, the arrow points from his left eye to her right eye

  • nice video

  • How do you manage to get a PD reading from an old pair Glasses? Thanks.

  • Today I got an eye exam and I was measure at 61.5 PD but when I got one before my PD was 63. My glasses I have on now is 63. How much of a difference is this? I am thinking to get smaller PD glasses but won't if it's not a big deal. So some reason I see better with glasses than contacts. Weird I think.

  • I get this video thanks but what about other things like how wide is the bridge of the nose and width of the face / because of your good video here I think I will order from you again thanks for the help

  • I found a 20 year old prescription with a PD of 72. would that still be valid now??

  • Thanks! I was trying to fill out an online prescription for Civil Eyewear, and this was the last field option… but I had no clue how to fill it out… Thanks!

  • Hi. And in people who have strabismus, does it perform exactly the same?

  • Hello, we appreciate your video and really liked your
    content, we also post videos on this topic and would love for you to take a
    look! Check out our latest videos on our Eye Talk channel.

    Keep up the good work.

    Thank you.

    The Eye Talk Team.

  • Why bigger the PD and smaller the glasses get? Shouldn’t they be bigger

  • My PD Is 66.5, should I use 66 or 67?

  • Why dont u make this pd ruler available as a print out? It would be easier

  • how do i measure the size of my pupils and iris at home if i wanna buy contacts online?

  • Zenni Optical has a PD ruler that you can print out.

  • Try the new "Eye Measure" app if you have an iPhone X. Uses FaceID hardware and is super accurate. Does near and far which is great for bi-focals.

  • Thanks for Information…

  • I've worn glasses for over 50 years, and never had a problem until last time. They had to remake them twice. Each time somebody different measured me, and each time they got different measurements. After the third time I was ready to give up and go someplace else. Still can't see very good out of my glasses. They said it was me. I told them I'm old enough to be your dad, and I've been wearing glasses for a lot longer than you've been alive, and never had this problem before. Even when reading my cell phone, the middle is clear but the outsides are blurry. I understand that I have to turn my head with progressive lenses, but the field of view is so narrow it's like looking through a tube.

  • I had my picture being taken while holding a credit card in front of my eyes and used to measure my PD using a caliper for most possible precision. The problem is I am getting almost the same value for both far PD (65.0mm) and near PD (64.6mm). I read around that there must be about 3mm or so difference between the two (far PD being greater than near PD). So why am I getting them almost equal? By the way, I have both myopia (~ -4.75) and presbyopia(~ + 1.75-2.0) and I did the measurement without having my glasses on. I did not put on my glasses because I know the distances change when being looked at from behind glasses (myopic glasses shrink the size of objects which results in obtaining a wrong value for PD). One explanation I can come up with is that my eyes actually can't focus on the far point where I look due to my relatively high myopia. I look into far distance without my glasses when I want to obtain my far PD but my eyes actually cannot focus on the far. If this is true, my far PD should be somewhere around 68mm while my near PD is probably correct at about 64.5mm?

  • อาชีพนี้ไม่ใช่ของคนใดคนหนึ่งเป็นของสาธารณะ

  • in Germany the specialist measured two PDs for my glasses, separately:
    -One between nose and left eye axis
    -One between nose and right eye axis
    For there is no symmetry in nature,

  • Thanks sir..

  • what is the importance of knowing your pd measurements

  • My eye specialist measured my of on auto computer and read as 69mm. Is that possible to measure through eye checking machine?

  • Hello everybody ❤️

  • Custom Make order PD ruler from dreamtrade.com.hk

  • I need to print  pd ruler

  • The way it should be is that the one who fits your frame measures your P.D. and your segment high. That is why this companies have trouble. The frame needs to be tested on the patient's face. Anything else is less than the standard of care.

  • mother fuckers didnt give me my PD! IMMA SLAP THAT HOE

  • i can't believe that he's serious about this

  • I just use an ordinary ruler😅😅😅

  • Right, because we all have that selectspecs ruler to hand! How about you use a normal ruler in an instructional video that most of the public have!

  • Fucking complicated and innacurate

  • SO IDOLS

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