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.
Sounds good huh?
HOW DO VARIFOCALS WORK?
Varifocals are something of a super lens.
They have a spectrum of focal power.
Ranging between close reading and distance, the lens graduates between these two corrective powers. Between the top and bottom of the lens, you, the wearer, can use the graduating focal strengths to assist your vision.
Rather than having one specific strength across the entirety of the lens (like single vision lenses) you can visually select ‘zones’ within a focal spectrum. This is how varifocal lenses offer visual correction to let you focus objects at various distances.
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 our lens prices, including varifocals, click here.
Cleverly, varifocal lenses have multiple prescription strengths built-in.
This is achieved by varying thicknesses on the front and back of the lens to create a vertically smooth “corridor” of corrected vision. This variability of focal power gives varifocal glasses their meaning and their name.
Varifocal glasses are used by people who require multifocal correction.
We’re guessing this might be you…
This basically means that your ability to focus at various distances is hindered. This 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.
Sounds complicated right?
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 are for multi-distance viewing for randomly occurring 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 are considered as a more specific use of lens.
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. Generally, this can be looking at your computer to observing objects further away across the office-space.
Occupational lenses are less busy in terms of focal strength but offer a more concise degree of visual correction for professional use.
Varifocal lenses are sometimes referred to as progressive lenses.
They can also be called multifocals, progressive powers lenses or progressive addition lenses (PAL).
These names all refer to the same lens type.
The name “progressive” comes from the gradually increasing/decreasing focal capacity of this lens type. From intermediate to distance correction, varifocals progressively graduate between the maximum and minimum lens strengths to help you see.
This multifocal scope is what gives varifocal lenses their name/s.
Bifocals and varifocals differ by the way in which they offer focal correction.
The major difference between a bifocal and a varifocal lens is the distribution of prescriptive powers.
How do bifocals work?
Bifocals have two defined sections within the lens, trifocals have three. This is characterised by a noticeable segment in the lens shape. As seen above, 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 further away.
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 the wearer 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 a pair of 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.
You might have heard the rumours about varifocals problems.
They have a bit of reputation for being difficult to get used to which is partially true but is perhaps a little bit overdramatic.
Learning to wear varifocal glasses properly is all about letting your eyes and brain adapt to this new way to see. A boundary-less lens with infinite viewing options. All it takes is some practice and patience to figure it all out
Here are some pointers on how to look through varifocals.
Distance: How do varifocals work?
If you want to focus on distanced objects, you’ll need to use the top section of your lens. You might experience the temptation to tilt your head forward to do this but eventually, your eyes will become trained to do this instead.
Near: How do varifocals work?
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 lens. For a while, you might find yourself tilting your head back to use this section of the lens.
Model A - GRY varifocal glasses frame.
If you’ve never worn them before, getting used to varifocals can feel a bit like you’re living in a fish tank or you’re underwater.
Sure, these aren’t examples of a sales pitch but these are common problems with varifocal glasses if you’re a beginner.
This aquatic sensation is created by distortions in the outer-edges on either side of your lenses. These deformations can feel a little disorientating, however, this is the compromise of having all that focal power in just one lens.
Persevere and you’ll unlock the potential of your new varifocal glasses.
If you’ve worn varifocal glasses before, it can take just a few hours to acclimatise to your new lenses.
If, however, you’re new to the game, it can take about two weeks to get a feel for your new varifocal frame.
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 speed things up for you.
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.
Model A - GRY varifocal glasses frame.
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.
Jamie Bartlett: co-founder
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