Bifocal Lenses - Uses, Pros, Cons, and vs. Progressives

What are Bifocals?

Bifocal lenses are divided into two distinct sections and optical powers. The top section corrects distance vision (myopia, hyperopia, or astigmatism) and the bottom corrects near vision (presbyopia).

People with refractive errors, which is when the shape of the eye disrupts light signals to the retina, need eyeglasses to help them see clearly. Bifocal lenses work by bending light to focus correctly on the retina (the light-sensitive layer at the back of the eye).

While all bifocal glasses function similarly and carry the same benefits, the visible line segment varies in style and appearance.

The different types of bifocal lenses include:

Half moon, also called D segment
Round segment
Executive (Benjamin Franklin), covers the entire bottom half of the lens
Ribbon segment, consists of a narrow rectangular area

Who Needs Bifocals?

As you age, you slowly lose the ability to shift focus between near and far objects. Many people develop presbyopia (loss of ability to focus on close objects) after age 40.³

Presbyopia is the most common reason people need bifocals.

Symptoms of presbyopia include:

Need to hold reading material at a distance to see clearly
Eye strain
Frequent headaches
Reduced reading vision in low light
Blurry vision when looking at small print
Trouble focusing on a computer screen

Bifocals also support focusing systems in children with certain eye conditions, including:

High myopia (using bifocals instead of single-lens glasses can slow its progression)
Amblyopia (lazy eye) requires a bifocal prescription to help with near-vision tasks
Accommodative esotropia (when one eye turns in to see near objects)

It may take children a couple of weeks to adjust to bifocal lenses. But it is essential to wear them full-time for optimal results.

Pros and Cons of Bifocals

Deciding what type of glasses to get can be confusing. If you have trouble with near and distance vision, it may be time to consider a pair of bifocal lenses.

While bifocals help you see near and far objects clearly, there are benefits and disadvantages you must also keep in mind, including:

Pros

The benefits and advantages of bifocal glasses include:

Only one pair of glasses (no need for reading glasses)
Cheaper than more advanced progressive lenses and buying two pairs of glasses
The visible lines help you know where to look for both near and far vision
Provide wider lens area for reading

Cons

It takes time to adjust to wearing bifocals
Visual distortions while you adjust, especially when going down the stairs
Having two prescriptions in one lens can be irritating and distracting
It does not correct for intermediate vision, which is used for computer use

When deciding what type of glasses to purchase, keep comfort in mind and talk with an eye doctor about what frames and lenses work best for you.

How Much Do Bifocals Cost?

The cost of eyeglasses varies depending on frame style, prescription, lens type, and if you have vision insurance.

The national average cost of single-lens eyeglasses without insurance is $531, which includes an eye exam, frames, and lenses.⁷

Bifocal lenses cost more than single lenses, with prices increasing at eye doctors’ offices compared to retail vision stores such as Costco and Walmart.

In addition to the eye exam, frames, and prescription, special lens treatments can add to the cost of bifocal lenses, including:

Lenses that tint and transition from light to dark
Anti-reflective coating
Polarized lenses (for sunglasses) that reduce glare while driving
UV protection
Scratch-resistant coating

Bifocals vs. Progressive Lenses

Eyeglass technology has advanced past single and bifocal lenses to include multifocal and progressive lenses.

Generally speaking, our vision is divided into three distinct areas:

Near vision (reading
Intermediate vision (computer use)
Distance vision (driving)

With bifocals, the distance vision is corrected in the top half of the lens, and the bottom half corrects near vision. There is a distinct line that separates the two halves.

A progressive lens has multiple prescriptions for all three areas of vision, but without a visible line. Progressive lenses gradually change prescription power as you look up and down.

While the absence of the bifocal line is more aesthetically pleasing, progressive lenses have a few drawbacks, including:

Smaller focal areas for each range of vision
Peripheral vision distortion when moving your eyes from side-to-side
Significantly more expensive than bifocals and single-lens eyeglasses
More extensive adjustment period compared to bifocals

Other types of lenses used to correct vision and refractive errors include:

Trifocals. These include a third prescription for intermediate vision
Computer glasses. These have multifocal lenses with a computer distance correction to prevent eye strain
Prescription sunglasses. These can have bifocal, trifocal, or progressive lenses

Summary

Bifocal lenses offer two prescriptions in one pair of eyeglasses. The top half corrects distance vision, and the bottom half corrects near vision. The two sections are divided by a distinct visible line. People with presbyopia (difficulty seeing close objects) are most commonly prescribed bifocals.

Progressive lenses are an alternative option to bifocal lenses. Progressive lenses correct for near, intermediate, and distance vision in one lens without the visual line but are significantly more expensive than bifocal lenses. Talk with your eye doctor about what lenses work best for you.

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