A common question opticians get asked is ‘What are the differences between Bifocals and Varifocals? The mere fact that they are known by half a dozen different names doesn’t help, so here is a quick and simple guide to help you.
The Bifocal is a lens split into two parts. The top part is normally for distance and the bottom part (or segment) is for reading. The lens can be modified depending on what they will be used for ie. Intermediate (computer) vision at the top and reading at the bottom is a common combination. A major benefit of a Bifocal is that it’s the easiest way to give a pair of spectacles two focusing points. They offer a very wide field of clear vision for both parts. The down side however, is that there is a sudden “jump” between the two parts and means there is a visible line in the lens. At first this can lead to a gap in the overall vision, so will take some time to adjust to.
Now to the Varifocal lens (also known as Multifocal or Progressive). This lens is more advanced and offers a very different way of viewing things than a Bifocal. The basic premise of a Varifocal is that it’s like a blended Bifocal, with an invisible line to provide seamless vision from distance through to reading, allowing the wearer to view objects at any distance. A drawback however is the width of vision available. Varifocals offer a clearer band of vision down the middle of the lens, but this means more distortion along the edge of the lens. This can result in more head movement when looking and focusing on objects, which could lead to a feeling described as “image swimming”. The key is to be patient and persevere and eventually these feelings will pass as the brain acclimatizes.
Overall, each style of lens offers you different ways of solving your visual needs. Together with an optician, you can look at the pros and cons of each option and choose the one that is right for you and your lifestyle.