No-line bifocals give you two separated fields of view. One is for reading and the other for the distance. Compared to that progressive glasses provide you with a smooth transition from the distance to the reading area and that all happens in one field.
Most people think progressive glasses and no-line bifocals are the same. That is not true. Find out in the table below what each lens design can do for you.
The differences between no-line bifocals and progressive lenses are listed here in this simple chart:
|No Line Bifocals||Progressive Glasses|
|What is it like to read with them?||Really easy. The reading area can be manufactured so bog you can do really wide eye movements||It depends on the add value. In most cases, you can expect a restrictive reading field which gives you 2-3 sharp articles in the newspaper|
|Transition if you look form the distance into near||The transition feels a little bit like a jump. Because you go form no reading power to full reading power in an instant||The transition feels very smooth. The reading power starts to add up the more you look down.|
|Which distances can be seen sharp||Distance and reading||Distance and reading and everything in-between|
|Limitations||If your eyes can’t accommodate a bit anymore it could happen that you have a blurry gap in die distance of your car dashboard. The reading field is too powerful and your distance field also won’t let you see sharp. You must either go nearer or further away to see it||Especially in the PC range and also in the close reading field the side are going to be blurry. Not a big deal for most people but you need to adjust to it.|
Which Is Better a Bifocal or a Progressive Lens?
Progressive lenses tend to be the got to solution for people over 40 because they look like your single vision lenses. Besides the popularity of progressive lenses, bifocals are oftentimes the go-to solution if people can not adjust to progressive lenses. The reason for the popularity can be also traced down to the visible distances of bifocals. If you are over 60 years old you will probably have a distance of around 3 feet which you can not see sharp. You have to either go further away to see it through the field for vision in the distance or you have to approach the object to see it clearly in the reading field.
This can be nerve-wracking if you want to see a price in the shop-window. Most people also associate the line in their traditional manufactured bifocals as “glasses for old people”. If you are using a laptop or a PC from time to time and you do not want to buy special computer glasses the progressive lenses are definitely the go-to for you. As we mentioned above in the table bifocals do not provide a dedicated field for seeing the pc monitor sharp. You could compensate this area with trifocals which add another line to your lenses.
You can eliminate the line of traditional bifocals with those to examples: Shamir Duo, Free Form Bifocals from Beta Optik. But you will definitely get the blurry gap as your eyes can not compensate for the near range anymore. Most people are wearing an anti-reflective coating to prevent their eyes from irritating mirror-like effects on their lenses. What happens in classic bifocals is that the edge of the reading window is more visible and can produce such effects. You are constantly aware of the window for near range tasks. Some people love it because they can find the reading window so easy compared to progressives where you need to test where the sharp reading area is.
We recommend going with progressives first. Because the benefit you get from a smooth transition between distance and the reading power oftentimes outweighs the smaller area of reading.
If you need a lot of power in your reading glasses the reading area will be a lot smaller in a progressive lens compared to a bifocal one. The size of the reading area varies for the progressives and the stronger it has to be the smaller your field of view gets. Usually, the add power of the reading field varies from +1,00 to +2,50D. If you are closer to an add value of +1,00 you can expect a very wide reading area but if you need an add reading power of +2,50D you can expect a pretty restricted field and it may be a good idea to supplement your progressives with a dedicated single vision lens for reading.
Going back and forth with your classic bifocals (such as with the line) between the distance and the reading power can cause some dizziness because most traditional bifocal lenses produce a slight jump of the picture while switching the field of view. You don´t have this picture jumping effect in special types of traditional bifocals, new bifocals like the Shamir duo and you certainly never experience a jump in progressive glasses.
If your glasses are not perfectly fitted like the pantoscopic tilt is higher than it should be another angle does not sit like it should be aberrations will come up. Those effects usually tend to make the image a little blurry. You can experience this effect if you look through your glasses and while you grab the temples tilt it and watch what happens. In progressive glasses, this effect comes more into play. It can even change the size of the reading area or the part which is meant to be for distance vision. It largely has to do with you looking through the glass from another angle. Oftentimes people experience this effect while driving.
While driving a lot of people are used to do big eye movements. Looking into the mirrors from side to side while switching the lanes. However, with progressive lenses, you are practically forced to move your head more with you as you look in a certain direction. The reasons are aberrations that cause a blurry image on the sides. This effect is enhanced if you are looking behind you because you want to cross lanes and make sure there is no other car. A lot of people hold their heads in an oblique position and what happens is they are looking straight through the blurriest part of the progressive lenses. That usually does not happen with bifocal lenses because there is still a sharp area for you to see (depending on the size of the reading field you choose).
If you are still not sure about what lens design is the right choice for you just go out and test them. This will tell you what the lenses can do for you and where their limitations are as your daily driver. Most lens manufacturers give you a satisfaction guarantee so use it and return the glasses if you are not satisfied with the result but get this clear before you buy them. When a lot of prescription is packed into one lens you usually need to accommodate a few days that is totally normal.
I would love to hear your experiences with progressives or bifocals.
Just post them down below.
Best regards Michael Penczek