Today there is a wide range of lenses to correct presbyopia and other vision problems. Among them you will find lenses for short-sightedness, astigmatism and long-sightedness, as well as single vision, progressive and bifocal lenses, among many others. Apart from the vision problems they correct, these lenses also differ in the way they let us focus.
If you are thinking about progressive glasses, our progressive lenses guide explains what they are, which types exist, how much they cost and how to get used to them.
Of all the lenses mentioned above, the ones people confuse most often are progressives and bifocals. That is why, in this article, we explain the main differences between progressive and bifocal lenses so you can decide which one suits you best.
What is presbyopia?
We have all seen someone wearing glasses whose lenses seem to be split in two, people who slide their glasses down to the tip of their nose to see up close, or even people who squint to try to focus on something far away. All of this, especially in older people, is a sign of presbyopia, that is, the loss of near vision caused by age. To correct it, today we have two main types of lenses: progressive lenses and bifocal lenses.
Let’s look at the differences:
Bifocal lenses
Bifocal lenses are used to correct refractive errors that occur when we focus both far away and up close. They were originally created to correct presbyopia and short-sightedness at the same time, which is why they have that characteristic look, as if there were two lenses inside a single lens.
In any case, bifocal lenses work the same way our eyes do, so it helps to understand how our eyes behave when we focus far and near. When we focus on something close, we normally look down by around 15-20 centimetres; when we focus on something far away, we raise our gaze until we are looking straight ahead. That is why bifocal lenses have the near prescription at the bottom and the distance prescription at the top.
As you can imagine, the jump between the two zones is very abrupt and getting used to it can be uncomfortable. On top of that, with today’s technology, bifocals are rather awkward to use with computers and tablets, because they have no intermediate zone: only distance and near, while we tend to look at a computer from a medium distance.
Progressive lenses
Progressive lenses, also known as varifocals, came along to replace bifocal lenses, which have now practically disappeared. Why? Because progressive lenses give good focus at near, intermediate and far distances. This makes the transition much smoother than with bifocals, and it is achieved because the lower part of the lens is designed for near vision, the middle part for intermediate distances and the upper part for distance vision. What’s more, modern lens technology delivers great precision, making the transition between zones even smoother.
It is true that one of the most widespread myths about progressive lenses is that they are hard to get used to, but nothing could be further from the truth. Progressive lenses have evolved a great deal to make adaptation as quick and easy as possible, so that when presbyopia appears, people can carry on with a normal life in their glasses without problems such as headaches, uncomfortable postures or general discomfort.
Now that you know the differences between progressive and bifocal lenses, what do you think? Which would you choose? At Lens4Glasses we work with several manufacturers of progressive lenses that will give you the comfort and sharpness you need to see clearly. All you have to do is send us your prescription and your favourite frame, and we will find the most suitable lens and coatings for you. You can see the price of each option in the configurator, and if you have any questions, feel free to contact us by email, phone or through our social media.