What is the Difference Between Bifocal and Varifocal Lenses?

Introduction

At some point in life, around the 40s, most of us notice a shift in our vision. You’re reading a message on your phone, then you suddenly look up at something across the room. When you try to look at your phone after that, your eyes take a second longer than usual to adjust. You pull the phone further away and then up close, trying to read the text clearly. This is the beginning of a condition called Presbyopia, where your eyes struggle to focus on closer objects as a natural part of ageing.

This is where you have to look out for solutions like bifocal or varifocal lenses. Both lenses are designed to help you look at near and distant objects without switching between different pairs of glasses. However, they do it differently, feel different to pair, and suit people with different lifestyle needs. This blog covers everything you need to know before making a clear choice for you or your loved ones.

What are Bifocal Lenses?

The simplest explanation of bifocal lenses would be combining your distance vision and near vision prescriptions into a single pair of glasses. Benjamin Franklin is widely credited with inventing bifocal lenses in the 18th century. Although the technology has evolved significantly over the years, the core idea remains the same. The bifocal lens is split into two sections with different optical powers.

The top part of the lens is to correct your distance vision. You can use that section for tasks like watching TV or driving. On the bottom part, you will see a small segment often shaped like a D or a circle. It’s designed to correct your near vision, and you can use it for tasks like reading or looking at your phone. There is a visible line separating the two zones. That line marks the transition from one prescription to the next. The design is very simple. You need to look at the upper part of the lens for distance. On the other hand, you look down for close-up tasks like reading. After a shorter adjustment period, most people find it very straightforward to use.

Different Types of Bifocal Lenses

Bifocal lenses come in different styles as well. The most common type is D-segment or flat-top bifocal. In this design, the near vision section forms a flat-topped half-circle at the bottom of the lens. Another popular design includes a round segment bifocal, which looks slightly smoother but covers a smaller reading area. Your optician might suggest a style depending on your prescription and lifestyle.

What are Varifocal Lenses?

Varifocal or progressive lenses also solve the same problem, but with a more modern approach. Instead of two fixed viewing zones with a line between them, they offer a gradual shift in prescription from top to bottom. The top of the lens handles distance vision, and the bottom corrects near vision, similar to bifocals. However, there is a gradual transition zone in between as well. The good part is that the middle zone corrects your vision for intermediate distances. It makes tasks like using a computer screen or looking at products on supermarket shelves easier for you.

There is no visible line separating the different viewing zones, and there are no abrupt jumps either. The power changes smoothly and continuously, which is where the name "progressive" comes from. Since there are no visible lines on the lenses, it’s hard to differentiate them from a normal single-vision lens from the outside.

The far left and right edges of varifocal lenses are slightly softer, especially in standard varifocals. This is a natural result of the lens design, also known as peripheral blur. However, modern varifocals like the ones you get at Specscart use digital surfacing to ensure the widest possible peripheral vision. You barely notice any softness in vision with these advanced lenses. You can learn more about how varifocal lenses work for a better understanding of the same.

Comparing Bifocals vs. Varifocals

Who Actually Does Well With Bifocals?

Bifocals are a good choice for people who want a simple solution to presbyopia. However, their lifestyle should be simple, where they mainly switch between tasks like reading or driving without significant screen exposure. Some people also have difficulty adapting to varifocals, and bifocals can be a good alternative for them. However, with modern technical advancements in varifocal lenses, this should rarely be the case. Another reason to consider bifocal lenses is budget constraints. People on strict budgets can go for bifocal lenses because they’re usually cheaper than varifocal lenses.

Bifocal lenses in the UK typically start from £30 for the basic ones. Depending on the lens quality, good quality bifocal lenses can cost £50 to £80, while premium ones can even cost upwards of £100 to £150.

Who Tends to Do Better With Varifocals?

If your day involves a mix of reading, screen time, driving, and tasks that require moving between distances constantly, varifocals are a better fit for your lifestyle. People working on the screens usually complain that bifocals leave them squinting at the monitor all day to get clear vision. The screen sits at an awkward distance that doesn’t fall cleanly into either bifocal viewing zones. Varifocal lenses naturally take care of this with their intermediate corridor in the middle.

Varifocals are also a great option for people who want one pair of glasses to do everything. You don’t need to switch between reading glasses and distance glasses based on the task or to see something that falls between the ranges. Since they look like single-vision lenses with no visible lines, they’re also a great choice for people who are conscious about how their glasses look.

Varifocal lenses can start from £40 for basic ones with significant distortion at the edges. However, mid-range freeform varifocal can cost somewhere between £99 and £150. When it comes to premium digitally surfaced varifocal lenses, they start upwards of £200 and can go even higher than £400 at high street opticians.

Specscart completely changes all this with our promise of making quality eye care and eyewear accessible to all. We only sell premium quality digitally surfaced varifocals customised to your individual measurements, starting at just £84. The best part is that it also includes coatings like anti-glare, anti-UV, anti-scratch, and impact resistance for free. When you combine them with our 2000+ premium and fashion-forward frame styles at 70% lower prices than the high street, you get an unmatched deal.

To Sum it Up

To be honest, varifocal lenses are hands down a better option for a modern lifestyle. They give you better aesthetics and correct vision across all distances in a smoother manner. Since they are customised according to your individual measurements and also cover intermediate vision for screen usage, they make your life easier. Bifocals, on the other hand is a good choice for people on a strict budget or people with very specific visual needs.