Bifocal vs. Trifocal vs. Progressive Lenses

Wondering if you should go with a bifocal, trifocal or progressive lens for your next pair of glasses?

Each one has distinct advantages and drawbacks, so it’s worth taking a closer look at the differences between them.

Let’s get to it!

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Bifocals, Trifocals or Progressive Lenses – Which Should You Get?

When it comes to your vision, bifocal, trifocal and progressive lenses all have the same basic aim: correcting presbyopia – an age-related vision problem that makes it difficult to focus on close objects – while also providing clear distance vision too.

What Are Bifocal Lenses?

bifocals on an open book

Bifocals consist of two different lens powers that are divided by a visible line. The top portion is for distance vision, while the bottom portion provides magnification correction for near-vision tasks like reading or sewing.

Bifocal lenses offer crisp, clear vision correction but may cause an abrupt change in focus when looking up and down.

Bifocal Safety Glasses

How Bifocals Work

Bifocals allow you to see clearly both far away and up close with the same pair of glasses.

The upper area of the lens is used for distance vision while the lower portion of the lens has an ADD (or magnification) power to help you see close objects or read clearly.

The ADD power is denoted with a “+” number (e.g., +1.50 or +2.00), while the distance vision power may have no sign or a “-” symbol on your prescription.

Types of Bifocals

All bifocals correct for distance and near-vision viewing. However, the actual lens design can vary:

Flat Top Bifocal – This type of bifocal has a flat top and round bottom, also known as a D-segment or half-moon.

Flat Top Bifocal

Executive Bifocal – Also known as the Franklin-style bifocal, the reading lens covers the entire bottom area of the lens.

executive bifocal lens
Executive Bifocal Lens

Round Segment Bifocal – This type of bifocal has two concentric circles where the reading segment is round instead of flat at the top.

Ribbon Segment Bifocal– This bifocal has a reading segment that’s shaped like a thin rectangle or ribbon across the bottom.

What Are Trifocal Lenses?

Trifocals are similar to bifocals, except they have an additional third (“tri”) segment that helps with intermediate vision – allowing you to see clearly at a distance of about two feet away such as computer screens.

How Trifocals Work

Trifocal lenses are designed with three different lens powers, each separated by visible lines.

Like bifocals, the top portion is used for distance vision and the lower portion provides magnification correction for near-vision tasks like reading.

In between these two, the middle segment offers correction for intermediate vision and allows you to focus on objects located about two feet or an arm’s length away from you.

Types of Trifocals

There are a couple of main trifocal lens designs:

Flat Top Trifocal – Like the flat top bifocal, this type of trifocal has a D-shaped close-range viewing segment at the bottom. The intermediate viewing segment is situated right above the reading segment to form the D-shape or half-moon lens.

flat top trifocal

It does not span the entire lens, preserving your peripheral vision. This is the most popular style of trifocal and the easiest to get used to.

Executive Trifocal – Also known as the Franklin-style trifocal, each segment spans the entire width of the lens.

What Are Progressive Lenses?

Progressive lenses, or progressive addition lenses (PALs), are a type of multifocal lens that provides clear vision at all distances with no visible lines or segmentation.

Instead, the power in each area gradually changes as you look up and down through the lens.

progressive lens diagram

This allows for a smooth transition between distance, intermediate, and near-vision.

Besides a more gradual transition from one field of vision to another, people also like that the seamless transition doesn’t scream “reading glasses” like bifocals or trifocals do.

How Progressives Work

Progressive lenses use advanced optical technology to create a continuous lens, eliminating the visible segmentation of bifocal or trifocal lenses.

The power of each segment is tailored to your individual prescription so that you have clear vision at all distances.

The lens gradations usually have an hourglass shape with the narrowest portion located in the middle.

The top of the hourglass zone is used for far-vision tasks like driving; the middle section helps with computer or arm’s length vision; while the bottom area is reserved for close-range activities like reading.

woman holding progressive glasses

Types of Progressive Lenses

Standard Progressive – This is the most common type of progressive lens for correcting reading, intermediate, and distance vision.

High-Definition (HD) Progressive – These lenses are more technologically advanced and offer clearer vision at all distances with virtually no peripheral distortion. They are digitally surfaced and provide a wider field of view compared to standard progressives.

Computer Progressives – These lenses are designed specifically for people who spend a lot of time looking at digital screens. They have larger intermediate viewing segments than standard PALs for viewing computer monitors or other digital devices about an arm length’s distance away.

Occupational Progressives – Specialized occupational multifocal lenses, such as double-D segments for electricians or auto mechanics, are available for those with specific activity vision needs.

Bifocals vs. Trifocals

woman choosing reading glasses

Now that you know the difference between a bifocal vs. a trifocal lens, which one should you get?

Bifocals offer a simpler design with just two distinct viewing zones: far-vision and near-vision. This allows for larger far and near vision segments since there’s no intermediate zone to worry about.

However, bifocals don’t provide a true intermediate vision correction between the two viewing zones so the adjustment from viewing far to near can be jarring.

Trifocals, on the other hand, correct all three visual ranges: far-vision, intermediate vision, and near-vision. Although this makes it a more versatile lens than bifocals, it also means that each individual power segment is smaller in size.

You’ll need a frame with a large enough lens to accommodate the three segments.

If you don’t find yourself needing the intermediate viewing segment, then bifocals may be a better option for you. But if you need the ability to read or do computer work at an arm’s length away, trifocals are probably your best bet.

Both types of lenses require some adjusting to, so the best option is to consult with your eye care professional and try out different types of lenses until you find the one that works for you.

In terms of cost, bifocals tend to be more affordable than trifocals, as they are simpler to manufacture and require fewer components. Trifocals also tend to be slightly heavier than bifocals due to the additional power in each lens.

Finally, both bifocal and trifocal lenses can come in a range of different styles, including flat-top or round-top designs. Flat-top bifocals and trifocals are the most popular, and they provide a wider field of vision in each segment compared to round-top lenses.

Trifocals vs. Progressives

If you know that you want correction for all three viewing ranges but aren’t sure whether to go with trifocals or progressives, it’s best to consult with your eye doctor.

Trifocals provide a clear line of demarcation between each power range which can be helpful if you’re trying to adjust to multifocal lenses.

They also offer better peripheral vision than progressives, particularly for close-range activities like reading or using a computer.

However, trifocals are less customizable than progressives.

man trying on glasses

Progressive lenses offer a more natural transition from one power range to the next compared to trifocals. They also look better aesthetically since there aren’t any visible lines.

On the other hand, progressives can be harder to adjust to than trifocals, as some people find the transition from one power range to the next disorienting.

They’re also more expensive than trifocals since they are more technologically advanced and customizable.

In Summary

When it comes to multifocal or varifocal lenses, there is no one-size-fits-all solution. Each offers its own set of pros and cons that should be weighed carefully depending on your individual needs.

Bifocals are typically the most affordable option with two distinct viewing zones and a simple design. Trifocals offer the benefit of three distinct power ranges, but may require a larger frame and need to be adjusted to.

Progressives provide a more natural transition between power ranges, but are significantly more expensive and often harder to adjust to than lined multifocal lenses.

Ultimately, it’s important to consult with your eye care professional in order to determine the best lens for your specific vision and budget.

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