Progressive Lenses Vs. Bifocal Lenses (Spoiler: Both Are A Bad Idea Because ..)

A bifocal lens is a single spectacle lens holding two optical powers separated by a visible line: distance correction above, a close-up reading segment below. Progressive addition lenses, also sold as varifocals or no-line bifocals, replace that line with a gradual power change. That change forces unwanted astigmatism into both sides of the lens, and it cannot be engineered away.

The difference is measurable. Progressive lens wearers had an adjusted odds ratio of 2.23 for falling compared with bifocal wearers (Lord et al., Optometry and Vision Science, 2025). Multifocal wearers fall roughly 2.3 times as often as non-wearers (Lord, Dayhew & Howland, Journal of the American Geriatrics Society, 2002). A randomised controlled trial found that switching active wearers to single vision distance glasses reduced falls (Haran et al., BMJ, 2010).

Why that happens, and what to wear instead:

So you are looking to figure out if you want progressive or bifocal lenses.

Spoiler:  Who gives a sh*t.  

Both will f*ck your vision in multiple more ways than your regular glasses ever did.

Source?  Receipts?  I’m Jake Steiner, I spent 20 (very long) years in vision biology science research.  I’m the guy that your optometrist hates more than his wife and his spoiled horrible attitude teenage goth kids.  

Also.  I’m the only guy in the known universe who published myopia reversal (eyes getting better) data, ever.  

Ever, ever.

That’s right all the lens sellers (“eye doctors”, heh) wish you I didn’t exist.  And that you don’t keep reading this article.  Or thinking for yourself.  So … close this page now, be a good little glasses subscriber, eh? 

Short version, difference between the two types of glasses:  One insert one mini area for close-up, the other segment the lenses.  Both totally f*ck your focal plane, they mess up your natural eye movement, they cause hyperopic defocus on your retina, and they pretty much turn you even more into a semi-blind mole rat.  

As the sellers of these lenses want.  That way you can’t ever take any of it off.

tl;dr:  Get neither of these stupid lenses, single vision is what you want.  If you need two, buy two.  Save yourself getting old prematurely because your visual system gets all messed up.  Or if you want to get all hardcore and FIX your eyes, check this.

On to the boring stuff: 

What Is A Bifocal Lens?

A bifocal lens is a single spectacle lens with two distinct optical powers separated by a visible line: distance correction in the upper portion, and a close-up “add” power in a segment at the bottom. Progressive addition lenses (also called varifocals, no-line bifocals, or multifocals) do the same job with a gradual power change instead of a line, which is exactly where their problems start.

What Is The Difference Between Bifocals And Progressive Lenses?

Bifocals have two focal planes and one hard boundary. Progressive lenses have a continuously changing corridor of power, and that corridor forces unwanted astigmatism into the sides of the lens. That peripheral distortion is not a manufacturing defect and no premium brand removes it. The same marketing logic drives the Eyezen upsell.

The governing rule is Minkwitz’s theorem (Sheedy & Campbell, Optometry and Vision Science, 2005): along the clear corridor of a progressive lens, unwanted astigmatism to either side increases roughly twice as fast as the reading power increases down the lens. The stronger your reading add, or the shorter the corridor in a small fashionable frame, the worse the peripheral blur has to be.

The consequence people miss: that distortion can be redistributed across the lens, but it cannot be reduced. Wider reading zone means worse periphery. Softer periphery means a narrower corridor. Every “premium” progressive upgrade is moving the same fixed quantity of distortion around your field of view.

Are Bifocals Better Than Progressive Lenses?

For anyone who walks around, yes. Progressive lens wearers fall measurably more often than bifocal wearers.

• Progressives roughly double the odds of falling compared to bifocals. In a 2025 analysis in Optometry and Vision Science, Lord and colleagues split 281 habitual multifocal wearers by lens type. Progressive wearers averaged 2.31 falls per person over the follow-up against 1.61 for bifocal wearers, an adjusted odds ratio of 2.23 (p = .03).
• Multifocal wearers fall about 2.3 times as often as non-wearers. Lord, Dayhew & Howland, Journal of the American Geriatrics Society, 2002, in 156 people aged 63 to 90. Multifocals measurably degraded distance depth perception and edge-contrast sensitivity, the two things you need to see the edge of a step.
• Your foot placement gets less precise. Johnson, Buckley, Scally & Elliott, Investigative Ophthalmology & Visual Science, 2007. Average toe clearance did not change in multifocals, but the variability did. You do not trip on the average step. You trip on the one that came in low.
• Taking them off during activity reduces falls. The VISIBLE randomised controlled trial (Haran et al., BMJ, 2010) gave single-vision distance glasses to 606 multifocal wearers with a mean age of 80. Falls dropped for those who took part in regular outdoor activity. Worth stating honestly: for wearers with low outdoor activity, the switch may have been harmful.

Note what the bottom of a progressive lens is doing while you walk. It is a reading add focused at roughly 40 centimetres. The ground is at about 150. The part of the lens you look through to see the floor is the part guaranteed to be out of focus for the floor.

Why Do Progressive Lenses Cause Headaches And Dizziness?

Because the distortion in the periphery corrupts optic flow, the visual signal your balance system uses to know how you are moving. Sauer and colleagues (iScience, 2021) ray-traced real progressive lens distortion and rebuilt it in VR. When gaze passed through the peripheral zones, subjects on flat ground perceived themselves drifting upward. Through the centre of the lens, no meaningful error.

So the reliability of your vision stops being constant and becomes a function of where you are looking. Your brain gets one answer from your eyes and a different one from your inner ear, and that mismatch is what produces the headache, the swimming feeling and the dizziness that new progressive wearers are told to “just adapt” to.

You also adapt in a way nobody mentions. Rifai and Wahl (Journal of Vision, 2016) tracked eye and head movement in progressive wearers and found a distinct signature: the eyes stay closer to centre and the head swings instead. That is why people in progressives turn like a tank turret. Every one of those head turns is extra work for your vestibular system.

Do Bifocals Or Progressives Make Your Eyes Worse?

Both put a permanent close-up add in front of your eyes, which means hyperopic defocus on the retina whenever you look through the reading segment at anything further away. That is the stimulus associated with myopia progression. A bifocal at least confines it to a defined segment you can learn to avoid. A progressive smears it across a corridor and blends it into the periphery, so there is nowhere clean to look.

For stopping myopia progression (or even reducing myopia), step #1 is to prevent hyperopic defocus and excess strain. In cases where existing lens use is over -2.00 diopters, this usually means a reduced diopter correction for your close-up use.  All of this of course is explained in great detail in the differential glasses topics. As with most endmyopia things, there are a seemingly endless number of edge case scenarios.

Edge Case:  You Change Between Distance And Close-Up Frequently

Today we’ll briefly look at one such case:  You need differential glasses, but you change between close-up and distance at short intervals, for extended periods, regularly.  Basically you need close-up distance and far distance vision at the correct respective diopter, ideally without continually changing glasses. One solution for this is to wear lenses that include both close-up and distance diopters.   People have figured out that progressive lenses accomplish this.  I’ve written about why progressive lenses are actually not a great solution. A better option are bifocal glasses. If you’re not familiar with both, short version:  Bifocals have two focal planes built into one pair of glasses.  Progressive lenses have multiple focal plane ‘zones’. More complex, the progressive lens.  Not what we want here and endmyopia, where we want one simple clear focal plane change. If you are a member of our private Le Meow forum, you can check out this link discussing progressive glasses. In this thread I briefly explain why you want bifocals and not progressive glasses, and which type of bifocals tend to work best:

If you have a good general measuring system and are aware of eye strain, it’s easy enough to try this solution and see if it’s better or worse. Important.

Bifocals might be better than progressives. Just two focal planes vs. a graduated change. Not everyone agrees, see point above on quantifying. Generally though having a distinct close-up diopter and distance diopter works out better than multiple diopters in one lens.

Note also that there may be multiple types of segments available for the close-up diopter. Depending on the size of lens / frame, your preference, and how much time you spend in close-up vs. distance, you might prefer one type of segment over another. ‘Executive segment’ (again, if that’s an option) tends to work well when a lot of the time is in close-up mode.

Frame types matter more in this scenario. You want to be able to comfortably ‘reach’ both diopters with your eyes, without the optical centers being tiny (with small or narrow lenses).

Admittedly I’ve been out of the loop on lens buying for a while, and this scenario isn’t that common, and availability of lens types varies around the world. So above, just some plausible notes.

Lots of things to consider.

Remember, endmyopia is all about keeping things simple.  So as you look at these ideas and solutions, whenever possible, don’t add complexity.  If you can adjust your work flow, better to have single focal plane lenses than above solution.  You will have to train your eyes to look through the right part of the lens, you add extra-ocular muscle strain, you have a smaller focal point.  These are all compromises that only make sense if they’re the only way to avoid hyperopic defocus.

Otherwise, just have two pairs of glasses.  Simple works best.

Update, see my more recent post including a reader update, switching away from progressive lens glasses.

Cheers,

-Jake

Related: What’s Best For Your Glasses? CR-39 vs. Polycarbonate Lenses · bfscl

Bifocals And Progressive Lenses: Frequently Asked Questions

What is a bifocal lens?
A bifocal lens is one spectacle lens containing two optical powers divided by a visible line, distance vision on top and a close-up add segment below.

What is the difference between bifocal and progressive lenses?
Bifocals have two fixed powers and a visible dividing line. Progressive lenses blend the power change gradually with no line, which forces unwanted astigmatism into the peripheral areas of the lens.

Are bifocals better than progressive lenses?
For anyone moving around, the evidence favours bifocals. A 2025 analysis in Optometry and Vision Science found progressive lens wearers had an adjusted odds ratio of 2.23 for falling compared with bifocal wearers.

Why do progressive lenses make you dizzy?
Peripheral distortion in a progressive lens corrupts optic flow, the visual cue your balance system uses to sense self-motion. Research published in iScience in 2021 showed that gaze through the peripheral lens zones produces a false sense of moving upward on level ground.

Why do my new glasses give me a headache?
With progressive or bifocal lenses, the usual cause is conflict between what your eyes report and what your inner ear reports, driven by changing magnification and distortion across the lens surface, combined with the extra eye and head movement needed to find the clear zone.

Do progressive lenses increase the risk of falling?
Yes. Multifocal wearers fall roughly 2.3 times as often as non-wearers, and progressive wearers fall more than bifocal wearers. A randomised controlled trial published in the BMJ in 2010 found that switching to single-vision distance glasses reduced falls in people who were regularly active outdoors.

What is the best alternative to bifocals and progressive lenses?
Two separate pairs of single vision glasses, one for distance and a deliberately weaker pair for close-up work. One clear focal plane at a time, no corridor, no peripheral distortion, no compromise in the part of the lens you use to see the ground.