Ahhh, the enigma of varifocal lenses.
Verging on wizardry, these magical lenses are considered as one of the most effective lens types.
And quite right too.
HOW DO VARIFOCALS WORK?
Varifocals are something of a super lens.
They have a spectrum of focal power.
Ranging from close reading to distance, the lens graduates between these two corrective powers. These happen between the top and bottom of the lens, so you, the wearer, can use the appropriate part of the lens to assist your vision.
Rather than having one specific strength across the entirety of your lens (like single vision lenses) you can visually select ‘zones’ within a focal spectrum. This is how varifocal lenses offer multiple visual corrections in one lens so you can focus on objects near or far.
This focal spectrum is often referred to as a “corridor”. Seen in the image above, varifocal lenses compromise the outer-edges of the lens to create an adaptive vertical window. This occurs in the middle of the lens, often in an organic ‘T’ shaped section.
Being so advanced, varifocal glasses are understandably more expensive. They’re far more complex to make but boy are they worthwhile.
Varifocals are like having several pairs of glasses in just one frame.
For some advice on how to buy varifocals online, you should check out these 4 tips.
What does varifocal lens mean?
Varifocal lenses contain multiple prescription strengths ranging from close reading, intermediate and distance.
This variance is achieved by changing thicknesses on the front and back of the lens to create a vertically smooth “corridor” of corrected vision. This variability of focal power is what gives these lenses their meaning and their alternative name; progressives.
What are varifocal glasses used for?
Varifocal glasses are used for multifocal correction.
If you struggle with your close vision and distance vision simultaneously, varifocals help you with both these vision zones in one pair glasses.
This visual corrections can be caused by the onset of presbyopia, hyperopia, myopia, astigmatism or a mixture of several of these eye conditions.
To correct all of these conditions individually, you would have to obtain at least two different pairs of glasses.
Having multiple glasses frames can sometimes be quite helpful, however, varifocal lenses can overcome this with their multifocal capacity.
Varifocal glasses are easily characterised by your intended application; every day or occupational use.
Everyday varifocal lenses
These general use lenses are for multi-distance viewing for variable life-scenarios.
These lenses have more to cope with as they can be used to correct all three distances: close, intermediate and distance viewing.
Contextually, this can involve reading a book, typing at your laptop or looking at the television across the room; all from the same viewpoint.
Notably, these lenses are ‘busier’ in terms of focal strength. This means that their focal graduation is denser than an occupational lens because they have to correct more distances of vision.
Everyday varifocal glasses can also be used for driving but we’ll get onto that further down this article.
Occupational varifocal lenses
Otherwise known as "office lenses" varifocals like these are a little more fine-tuned.
Offices offer a more consistent environment where you tend to have a static vantage point. Varifocal lenses can be used to help you see intermediate and distanced objects from your “usual-spot” within the office.
Primarily, this means you can jump between using varifocals with computer screen work to then observing an object further away across the room.
In short, occupational lenses provide a more concise degree of visual correction suited to a more consistent environment.
What is the difference between varifocal and progressive lenses?
Varifocal lenses are sometimes referred to as progressive lenses, but they are actually the same type of lens.
This alternative name comes from the progressively increasing/decreasing focal capacity of this lens type. From close, to intermediate, to distance correction, varifocals graduate between the maximum and minimum lens strengths to help you see.
Other names may include multifocals, progressive powers lenses or progressive addition lenses which all refer to the same lens type.
This multifocal scope is what gives varifocal lenses their name/s.
What is the difference between bifocal and varifocal glasses?
The major difference between a bifocal and a varifocal lens is the distribution of prescriptive powers.
- Bifocals contain a close reading lens segment within the lens
- Varifocals have no segments within the lens
How do bifocals work?
Bifocals have two sections within the lens. This is characterised by a noticeable segment in the lens shape.
These can be different shapes of segment such as a round shape, a D shape or a dissecting split across the lower third of the lens.
The lower segment in the lens is usually smaller and is generally used to correct close-distance reading within 35cm. The upper, more major part of the lens is used to correct distance vision for objects beyond arm's reach.
You can visually alternate between these two lens segments depending on what you wish to focus on, near or far.
How do varifocals work?
Varifocals differ to bifocals as they have no identifiable segments within the lens.
Instead, they have a gradual change in focal power which graduates from the top of the lens to the bottom. This creates a smooth and gradual spectrum which allows you to find the correct zone within the lens to focus on various distances of objects.
Without the interruption of segments or divisions, this makes varifocal lenses appear more aesthetically pleasing than bifocal lenses.
They’re just that bit…sleeker.
If you decide to invest in varifocal glasses, getting used to them can take a little bit of practice.
Read below for some tips on how to get used to wearing varifocal glasses.
How do you wear varifocal glasses?
Learning to wear varifocal glasses requires practice, knowing which section of the lenses to look through to see.
For close vision, the lowermost section. For intermediate, the middle section. For distance, you look through the upper section of your lenses.
Here are some detailed pointers on how to look through varifocals.
If you want to focus on distanced objects, you’ll need to use the top section of your lenses. You might experience the temptation to tilt your head forward to do this but eventually, your eyes will become trained to do this instead.
If you want to focus on distanced objects, you'll need to look through the middle section of your varifocal lenses.
If you want to see closer objects such as your phone, you’ll want to use the close-reading section in the lowest portion of your lenses. For a while, you might find yourself tilting your head back to use this section of the lens.
Are varifocals easy to get used to?
If you’ve worn varifocals before, it can take just a few hours to acclimatise to your new lenses.
If you’re a novice however, it can take as long as two weeks to get used to using them.
Adaptation will eventually happen if you allow yourself to form the necessary habits of helping you see through your new varifocal lenses.
Here’s some tips to help you get used to the new side effects of varifocal glasses.
Varifocals and driving.
Wearing varifocals for driving is a common usage.
With their graduating focal power, varifocal glasses will be able to help you see at various distances which can be very helpful when driving your car.
Before you jump behind the wheel, it’s best advised that you become fully accustomed to using your varifocal lenses.
This might seem like common sense but you need to be fully adjusted to them in order to safely operate a car.
As varifocals graduate between focal strengths, it’s a good idea to choose a large rimmed frame. This will give you the maximum amount of lens-area to use; whether you’re in or out of the car.
For some people, the peripheral distortions of varifocal glasses are too difficult to confidently use when driving. If this is the case, you might want to consider having two pairs of glasses.
It very much depends on your prescription, your preference and whether you’re comfortable with how your lenses perform. For some, a pair of driving glasses with single vision or varifocal lenses is a better solution.
The main thing to remember is your safety and what you think will give you the most confidence whilst on the road.
How much do varifocals cost?
The cost of your varifocal lenses primarily depends on your prescription and any additional lens coatings you may require.
To calculate the cost of your lenses, please visit our lens calculator.