Here in this article you will find out how to order progressive lenses online and the limitations that come with it.
First before you get to any of the websites from online shops where progressive lenses and glasses are sold you should have some things prepared.
Step 1 Prepare Your Data
- Your prescription for distance and near vision
- The measurements of your pupillary distance and height of your pupils
- You already decided what frame you want to wear
When it comes to your prescription you should have data that looks something like this:
This data tells the manufacturer what big your myopia or hyperopia is with the value SPH. CYL stands for the amount of astigmatism you need and A stands for axis and determines in which position the astigmatism should correct your vision. All we talked about is for distance vision.
The Add value stands for the amount of reading power you need in your progressive lenses. The higher the reading power is the smaller your field of view will be in the lower half of the lenses. If you want to know what to expect exactly read this article here about the clear field of view in your progressive lenses.
The values Pr and B are seldom an option with online optical shops. Because the prescription gets more complex and as you will see some things will be gauged or averaged out instead of your optician’s measurements but more on this later.
So this process is pretty straight forward. You see the data on your sheet of paper and you basically need to copy and paste the values. But now comes the more difficult part. When you order progressive lenses online you need to do the centration process by yourself.
Step 2 Take Your Measurements
That means you need to measure where you are looking through the lenses. Those measurements are divided into horizontal values (pupillary distance) and the vertical distance the height in which the lenses should be placed.
Frankly spoken without the instruments in an optical shop this will probably go wrong but if you pay attention to the details I will point out you might end up with a decent spare pair of progressives.
When it comes to the centration your head should be placed in a natural posture and the you should focus on something that’s in front of you. Your eyes should point straight ahead because if you perform eye movements slightly to the side your lenses will be made this way. And your clear fields of view will be shifted sideways.
So you need to look ahead without performing eye movements. If you stand in a position that is unnatural for you like with your chin a little higher than usual your reading zones will be misplaced. So make sure you stand in your natural posture. The environment should be well lit and the frame should already be adjusted to your needs.
In my opinion, the easiest way is to take a photo. The camera should be at the same level as your eyes. In addition to that the camera should be pointed directly in the middle between your eyes. If it is shifted sideways again the whole centration will be placed more sideways. So your head and the camera should be perfectly in one line.
When you load up the photo you can note some reference points and the distance in between. As you scale the picture on the same size on your laptop the distance between your reference points should match your noted one before.
With this set up you can take out your ruler and measure the distance from the middle of your pupils to the middle of the frame. That is the pupillary distance for each eye. Then you can get the height by measuring the distance from the lower part of the frame straight up to the middle of your pupil for each eye.
This is really basic stuff and the minimum requirements for ordering progressive lenses online. But some online shops do not even require a height. They will just produce the lenses setting its position to the middle of the frame. In most cases, this will not work.
The reason is the pupils in most cases are located in the upper third of the frame and not exactly in the middle. Your optician usually uses devices to get the measurements right down to the tenth of a millimeter. With the DIY approach with your ruler or even some apps in combination with no experience, you will get to half a millimeter of error if you are lucky.
In most cases the error will be greater. The because of a lack of experience and accuracy in the measurement process. In a blog of a online shop you should repeat the measurement three times and then you should take the avarage of those measurements. I had to laugh out in this moment because three wrong measurements do not make the avarage right but whatever.
With everything, you know now about the basics of measurements lets dive into the measurements that are needed for the so-called premium progressive lenses. Those are the following if you want to know how to order your progressives online and measure by yourself:
- Vertex distace
- Pantoscopic tilt
- Wrap angle
If those parameters are used in the grinding process for your progressive lenses the position of the reading zones gets further fine-tuned to your needs. The result will be a wider field of view.
As far as my research went I did not even see the option in the online shops to type this information in. This is very sad for someone who wants to get the lenses in the same quality as in the optical shop. Those missing adjustments make the lens a more standardized product. And the outcome is a less clear field of view and less visual comfort.
The customization to you as a wearer will be missing and that is what actually leads to better a better experience with your progressive lenses. You can dive further into this topic with this study here.
Step 3 Measure Pantoscopic Tilt
The manufacturer of your progressive lenses needs to know in which tilt the frame will sit in your face. This way he can customize the prescription to your needs individually. If you watch the frame from the side you can see both they are tilted differently. If you draw a line straight down to the bottom you can measure the pantoscopic tilt.
Step 4 Measure Vertex Distance
When you want to measure the vertex distance the distance from your eyes apex to the back surface of your lenses is meant. Depending on the readjustment of your frame or your needs this distance will change. Generally it is recommended to minimize this distance. This way you will get a wider field of view in the reading distance.
Step 5 Measure Wrap Angle
If you want to measure the wrap angle you should look at the frame from above. Then you should measure the angle from the middle of the frame to the end of the frame.
If one of the angles is off in your measurement you will end up with blurry vision. Look at the short clip below. The lens is tilted and the nice focal point gets distorted immediately. What this means for your prescription is explained if you read on.
Some people take rulers for those measurements and some take photos. Both are valuable options if you can be sure about your measurements.
What Do the Individual Parameters Like the Vertex Distance, Pantoscopic Tilt, and Wrap Angle Do?
What happens when those parameters are used the prescription can change in lens power. If your myopia or hyperopia is higher like 8D the change will be more dominant and more subtle if your prescription is like 2D.
If the lenses sit a little further or closer to your eyes you will use another spot in the lens as you look down to read. In addition to that those parameters oftentimes lead to an altered prescription, not in every aspect of your lens powers.
Look at the picture above for a deeper understanding of the following information. Your prescription was measured in a certain setup. That means the lenses in front of the testing frame were let us say 13mm away from your eyes and they had a certain tilt to it.
If this setting changes compared to your normal frame you need a compensated lens power/ optimized prescription in your actual glasses. Look at the picture above again and compare the sphere power on the lower-left with the white background to the new sphere power with the yellow background.
There you can see the actual prescription and then the optimized prescription that is used to correct you best and to give you the widest field of view.
If this adjustment is not made your field of view can be generally a little impaired. Even in the upper half of the lenses! Like in the picture below. Of course, no one tells you that because A you bought premium progressive lenses (which means nothing) and B you save a lot of money.
Which Lens Design Do You Want to Order Short, Medium, or Long?
Depending on the height of the frame in general and your prescription it makes sense to go with different lengths of progressive lenses. With lengths the transition is meant from distance vision to full reading support as you perform eye movements.
I have an article about this topic here if you want to dive into this option. In short the longer the wider the field of view will be. But this of course requires you to look down more to reach full reading support.
And if you have a bigger difference in your left and right eye in your prescription you might into problems like headaches or double vision. This is something your optician checks for you. But this is no option when you buy progressive lenses online. At least I could not see this option in the shops.
Step 6 Decide What Coatings You Want to Have
If you order progressive lenses online go with the anti-reflective coating. Always get that in addition. It makes the lenses more transparent and will give you a more natural look. Because the person in front of you will have an easier time seeing your eyes properly. Instead of guessing where your eyes are because he looks at a glare just in front of your eyes.
Final Thoughts About Ordering Progressive Lenses Online
In most cases, you will get progressive lenses that are inferior to the ones in a local optical shop. Because you can not even type in the needed data for the high-end optimization. And wearing something from morning until you go to bed which is not ideal is probably not a good idea.
However, you can save some money if you go with the online shops. If your needed measurements are by chance pretty much close to the average values you might get decent performance out of them. But in most cases, you will not. And that is why I can not recommend this DIY approach.
But keep in mind my opinion may be affected because I am an optician with a little shop in Mannheim Germany. Depending on the kind of prescription you have ordered your glasses in general online can be even dangerous. Because a professional optician could react an optimize things right from the beginning that could cause headaches or double vision.
I wish you a great day