Eye Measurements – PDs


What is a PD measurement?

Your PD (Puplillary Distance) is the measurement between the centre of your pupils. This measurement is an important part of making sure your vision is correct with your lenses.

It is simply to ensure that the centre of the lenses sits exactly where the centre of your pupil is. If the measurement is done incorrectly, it can cause eye strain, making the lenses feel uncomfortable to wear, especially with strong prescriptions.

Some websites actually guess this measurement, or just use an average measurement. We take our duty of care to our customers very seriously, and would never just guess such an important measurement.

We strongly advise anyone not to buy glasses under these circumstances. Would you buy a coat from the internet, and have them guess your size? We’re all completely different, and very importantly, so are our eyes.

How will I know what my PD’s are?

You can ask your optician at the time of the eye test. If you feel uncomfortable asking this as you have no intention of buying glasses, don’t worry, we can take your measurements from your existing glasses. When you send your frame to us to be reglazed, we just need to know for certain that the lenses are your own old lenses, and if you wore them for distance or reading vision.

(The measurement for distance is slightly different from the measurement for reading.) From this, we can calculate the correct measurement required. If any of the above sounds confusing – don’t worry – just ring me on 01253 795 523 and I’ll be happy to help. If I’ve bought a frame on the internet, or want to use a frame that someone has given me, do I need to measure my own PD’s? Not necessarily.

You can send us an old pair as suggested below, or with the help of a friend just carefully follow the instructions on on how to measure your PD’s given below. The easiest way to find your PD measurement is to send one of your old pairs of glasses to us, in the box, with the frame that you want us to reglaze.

(All we need to know is, if your lenses in the old frame that we’re taking your PD measurement from were single vision, were they distance or reading glasses?)We can take your PD measurement from the old pair of glasses, then return them to you along with your newly reglazed pair of glasses.

How to measure your PD’s

All you will need is a marker pen, and the glasses that you want reglazing with your new prescription. 1. Sit facing each other about two feet apart at eye level. 2. Make sure the frame is sitting comfortable on the face of the person the glasses are going to be reglazed for. Adjust the nose pads a fraction if the frame feels too tight or too loose.

This is done by gently widening the pads or closing the pads a little at a time with your thumbs. 3. Once you’re happy the frame is comfortable, the measurement can be taken. 4. The person with the pen, close your right eye and have the other person look at your left eye, it is important that you don’t move your heads about. (Try not to laugh) 5. Keep still, while looking into the centre of each others eyes, (not the pen tip). Mark a dot on the lens where the centre of the pupil is.

WITHOUT MOVING YOUR HEADS, do the exact same process to mark the dot for the other eye. Now both eyes are marked with a dot where the pupils are, lean back a little and look directly into each others eyes. The person with the pen look to see that the marked dots are sitting directly on the centre of both pupils at the same time, without moving your head from side to side as this will alter the measurement. The measurement between the dots is the PD measurement.

Measure the distance with a ruler, and repeat a couple of times to confirm that you keep getting the same measurement. Leave the dots on the frame when you send it to us. We will take the PD measurements from the dots on the frame ourselves. This sounds a bit complicated, but really it isn’t. We advise that you practice a few times as you’ll probably laugh your way through the first couple of attempts.