Showdown Experiment: Will Enough Outdoor Vision Shorten My Eyes?

After going all out on eyesight measurement for a while, my result is still murky. What’s cause and effect here? Are my actions shortening my eyes? Are we really on the right track with outdoor vision and the Reduced Lens Method? Is Jake’s “standard rate” of improvement really possible for normal people?

To figure this out with higher confidence, I will drastically change my behavior for at least August, in an attempt to roughly double the stimulus available to my eyes. (More precisely, I already started, on the 30th of July.) During the experiment, I will:

  • aim for a daily minimum five hours of daylight outdoor distance vision.
  • make sure to take breaks from near work without fail.
  • shift my sleep times to use as much daylight as possible.

I won’t stop for anything short of health issues. If it rains all day, I’ll be out there with an umbrella for at least five hours. And after keeping this up for over a month, I will top it off with multiple weeks of biking through Italy.

As usual, I will measure my results (whenever I am home) and log axial length as well as focus reach (with measurement glasses).

The purpose of this is to confirm or question the claim that Jake’s rate of improvement of 0.25 dpt every 3–4 months through shortening of the eye is actually possible. This rate corresponds to roughly 1 µm of shortening per day, which should be well visible in my log. So there will be a quantified answer of how well this works.

Just posting this to announce it as a proper experiment. I’ll write updates once data starts rolling in. I’m motivated! Let’s do this! See y’all around, I’m going outside now. :cowboy_hat_face:

Main Result

The experiment was terminated after 80 days, a little earlier than planned. Click here for the corresponding update post.

Overall, the experiment had a moderate outcome. My eyes did not shorten at the proposed rate, but a rough estimate of change indicated shortening of 20 µm on my left eye, and 24 µm on my right – based on lagging EMAs, and not compensating for potential additional lag of the eyes’ response.

The experiment result suggests that simply piling on extra outdoor hours over a few months, using medium undercorrection, may work to reduce myopia, but high amounts of daily outdoor time did not seem particularly more effective compared to medium amounts of daily outdoor time. Of course, this was a short, N=1 experiment, so your results are likely to vary.


hmm, that’s good! but keep in mind that if you are just starting up, your eyes need an adjustment time from your old habits to your new habits. Just wearing differentials for close up will remove some of the eye strain, and wearing 0.25 weaker for normalized will create a blur horizon and your brain needs to adapt to this as well.

1 Like

Excited to see what happens! Your distance to blur measurements and axial length data are invaluable. (Frankly, your logs are the only reason I’m “out of the closet” about EM to certain people.) A lot here can be brushed off as anecdotal evidence, but what you do is so much more precise than that. Very much rooting for your experiment to produce some results :slight_smile:


In this documentary (english title “We will all be blind tomorrow?”) they say Taiwan introduced a 2 hour outdoor activities break in the school program and their myopia trend goes backwards since then.
So outdoor time must help against myopia.
Too bad other countrys won’t copy that concept until almost everybody needs glasses.


I should’ve added some context. I’ve been doing the Reduced Lens Method since spring 2018, and have done plenty of measurements where I captured both improvement and worsening and logged the configurations of glasses I used when each happened. I’m confident that improvement, including slight shortening of the eyes, has happened at the blur levels I’m aiming for.

Here’s a snapshot of my current log state:

Upper graph shows diopters to horizon, lower graph shows axial length in millimeters, as measured via laser interferometry (Zeiss IOL Master), where a single entry is the median of multiple samples. EMA refers to an exponential moving average, which is a trailing average weighting each new entry with 6% into the new average.

So, my axial length has been trending down on both eyes since March, except maybe for my left eye recently. But last winter, both eyes have elongated, so I can’t talk of long-term improvement in terms of axial length. So I’m perfectly used to the methods, but my improvement rate has been too slow to serve as evidence that this really works. This is why I’m trying to pull out all the stops to see if outdoor vision can really get this done.

I’m logging my daily outdoor distance vision time as well, so that we can confirm my compliance to the five hour minimum rule. So far, I’ve been above the threshold on the three days since I started.

As distance glasses, I’ll be using Eyebuydirect’s Pearl frame with -2.5 dpt sph CR-39 lenses. This offset should allow improvement, based on the undercorrections I used during times of improvement in the past. Especially with such a high amount of outdoor time and distance breaks.

I really want to turn this into a hard test of the method, so if anyone has doubts about the methodology, please speak up! For now, I’m off to bed, as I need to start shifting my sleep times to get more daylight time. :sleeping:


Stock up on the sunscreen, wear your sunhat and good luck on the ultimate vacation!


That’s great. Just to make sure, when you are out 5 hours daily, do you practice active focus? Otherwise just having a blur horizon won’t help much i’m afraid?

Also, when you read or do close up work with differentials, do you practice ‘print pushing’ ?

Quick question on the 5 hours outdoors…if you don’t have ciliary spasm, is 5 hours too excessive? We appreciate your drive in experimenting :slight_smile: Power to you!

I thought outdoors is to relax the eyes, and additional hours will only have marginal benefits if eyes are already relaxed.

1 Like

As usual, I’ll throw in the same old-man repeated commentary: Find a hobby.

Something that makes that distance vision time tempting, in itself. Hey, it could just be that 5 hour walks are a hobby, who knows (whenever I lived in nice larger cities - like Budapest for example, long walks used to be really enjoyable).

Anyway. I always say it, and it doesn’t translate in people’s heads, till they find something that really clicks with them as an activity. And then it’s suddenly … ahhhhh, that’s what you meant. Like when I picked up paragliding, five hours of outdoor time is suddenly nothing. No chore. Driving to the site, hanging out with people talking about nothing while waiting for wind, setting up gear, actually flying, breaking down gear, chatting some more … you eat up 5 hours quite easily. Never think about a screen, eyes always in natural distance ranges, and you filled those hours with memorable experiences and life well lived.

It takes a big step back, sometimes. Thinking creatively. I used to live in a Western country near the ocean. Seemingly “nothing to do”, as with everywhere. Found a yacht club with weekly sail races. I didn’t own a boat. Not a member. Can’t let those kinds of pesky details deter you, though. Life’s short, ask for forgiveness rather than permissing, whatnot-whatnot. :stuck_out_tongue: So I bought some nice craft beer six packs, showed up a half hour before race time. Wandered through the docks, asking who’d want an extra crew member and some beers.

Worked every time. Maybe not five hours worth but at least … 3. And quite fun.

Or finding the light sport little local air strips. Again, just show up early on Saturday morning. Bring some donuts. There will be random weird dudes getting ready to fly their random weird experimental contraptions. Quite a few of them will love to give you a ride, chew your ear off about building their aircraft.

Note that i’m a massive introvert, I don’t like people bugging me. But after enough solo time working, anybody can find the ambition for getting out there. And the opportunities, like above stuff, are truly endless. I used to do everything from regular police ride-alongs, to building old Corvette race cars with rednecks living in backwater swamps, to living in tents in Key West hunting lobsters. Bought a $500 limousine off Craigslist once, which turned the invited-to-everything social life to 11 and alll manner of non-screentime amusement. There’s really no way to run out of amusement, once you get the bug for living interesting moments on a grander scale. Big world out there, plenty of time before nine, and after five.

And it makes massive mountains of difference for eyesight. And it’s sustainable. And it’s fun to test drive various hobbies and activities. I think if measuring axial shortening is a goal, might as well aim for the moon and also add as many life crafting experiences along the way as possible.

Apologies if above is presumptuous or preachey or otherwise unnecessary. Granted everybody has their own ideas, there’s no better specific ways, everything is a valid personal direction. Not great with words and such at all times, I just get excited about new experiences.


@wanttoimprove while there’s no way to prove that I’m using Active Focus the same way others are, I’m fairly certain that I’m able to relax my ciliary and I am absolutely trying to focus at the distance. Any calibration mechanism of the eye must work under these conditions, or else I’d have to be a genetic defect. My ancestors surely didn’t require any super difficult to find techniques to be able to see in the distance. So, I don’t think that this would be a good explanation if this experiment should not show positive results.

For near work on the computer, I try to be in the range between the edges of blur of red and green contrasts. The original print pushing rules are underdefined with respect to chromatic aberration, so it’s not defined whether or not this is still print pushing, but I would say it’s not, as I always leave notable blur on blue contrasts. The last time I went closer than that was last winter, where both of my eyes elongated, so I wouldn’t recommend it for now.

@Mare I chose five hours to exclude the possibility that I’m lacking stimulus. The main point here is to find cause and effect.

There has to be something that creates the actual stimulus on the retina. Relaxing the ciliary body is probably not enough for that, or else all the Bates people with their palming would have great effects of shortening eyes. Various studies show that there’s something about axial chromatic aberration going on, and that eyes tend to fare better with lots of sunlight.

My biometrically validated improvement is too slow to reach @jakey’s standard rate of improvement. I suspect that I’m limited by some sort of signal. There are a number of possible explanations, but before blindly experimenting with these details, I have to check that the premise is sound, and that means that I have to see my eyes shorten significantly. If I radically increase my outdoor time, this will show me whether the premise is sound, and afterwards I can either question the premise (if it didn’t work) or concentrate on the more detailed conditions for improvement (if it did work).

@jakey I’m sure you’re right about outdoor hobbies! Will keep an eye out for any cool outdoor activities. For now, I’ve been doing things like jogging, biking, doing various errands on foot outside, eating outside when possible, and doing my bodyweight exercises outside when possible. These things don’t quite add up to five hours yet, but it’s a good start.

Another idea I had was going for audiobooks instead of reading books. Not really a new hobby, but it could add a whole lot of time for distance vision.


5 hours a day - I’m impressed!!! How do you manage…?
Then… remember our little chat in another topic about outdoor time? These sunny days, I think I actually do hang around 5 hours outside or more: I just spend that much time at my favourite lake… I might be reading a lot and typing on my phone some days.
(Also have done this before EM, so did it last year as well. Like Jakey said - it never occurred to me to count the hours!)

I recently cleaned up my balcony and put a nice chair there. Since, I’m reading there. It’s incredible, those cloudy days, when you need light inside to do everyday stuff - you can read perfectly well outside.

Stand Up Paddling might be something for you? Aside from the boards becoming cheaper and cheaper, there are nice people who’ll let you go for a ride - even without donuts or beer! :wink:

Since I visited (or was made to visit :rofl: ) a “bird show” (you know, like a zoo, watching eagles and other birds like that fly and they tell you lots of info about them), I actually enjoy watching birds - surprise surprise, had\t thought that when just accompanying someone to somewhere probably boring (it wasn’t, it turned out to be so cool!).

But maybe just reading outside would make a difference? I’m also eating on my balcony now, and trying to do as much as I can on my balcony when at home, relaxing my eyes with a look at the clouds.

@jakey, please don’t apologise for these kinds of posts - I find them truly inspiring!!!


Been thinking about methodology.

So you’re trying to test the jake method in general, and outside time plays a huge role.
I think you need to track carefully, because 1: more outside time might automatically result in less screen time - but since laptops and smartphones that is no longer true. Also, you crazy man changed your sleeping pattern! That made me gasp, I’m really impressed! Then I realized, I’m doing it as well: so hot in the office, get there early to leave early, on hot days…

So, you’d have to track carefully and note the little differences:

  • amount of daylight hours: sunrise & sunset at what time, hom many hours does that make?

  • % & amount of daylight/dark night hours you spend awake/sleeping as well as indoors/outside - I mean, could sleeping outside make a difference? Either at night, maybe even in the sunny morning?

  • indoors time with/without artificial light / using a lux meter all times here! How much of that is close up? I’d even cluster in: close up smartphone, close up screen (computer at work), close up books, close up else (anything where stuff is moving, drawing…), maybe tv if you watch
    Then there’s everyday indoor time. And maybe you look out a window a lot? What about driving, is watching from inside a car/train indoor or outdoor distance vision?
    I’d call it commute distance vision :wink:

  • outdoor time:
    Me right now, sitting on my balcony with my phone (bad kitteh!!). Yes it’s outdoors, but screen time as well. So track: how much of your outdoor time is close up, again: phone, screen if you use a laptop, “everyday vision” like your workouts where you don’t focus consciously on distances and then real distance vision (when on a bike) or even active distance vision (ad - I named it AD for me, those times when I focus on looking into the distance, while on my bike or hiking, reminding myself to really look far now, asking: what’s the most distant thing I can see. Can have this when looking out a window as well).
    Again, take notes of outside brightness (lux).

Just my thoughts, so you can figure out the little differences these things might make.

Btw: if you want some samples, I’ll drive by your city soon, could drop in for a little :eye: measurement, just pm me.


I just wonder, the word “outdoor” has 2 factors:

  1. Daylight
  2. Distance

Would this also work the same if you would spend time in a big house (10-20meters distance view) with a lot of full spectrum lights?


Imho, Jake encourages us to have a life outside of our tiny home bubbles. It’s more than just vision improvement, it’s about re-learning to do outdoors activities and not be slaves of our devices.

Concerning 2. Distance

I Don’t think distance really matters. it’s all about having a little blur on what you are trying to see or read, and then clearing it out doing AF or ‘print pushing’


Staying above five hours can be surprisingly difficult if you have a schedule to meet and there’s wind plus heavy rain just when there’s time to get outside. Got quite wet yesterday, even with an umbrella. I managed to stay above five hours though. :cloud_with_rain::sweat_smile::cloud_with_rain:

First measurement results are in, and they are on the poor side of both focus reach and axial length, though of course, none of it is remotely significant. It’ll take at least three weeks to make any reasonable statement about the direction of change.

@Tii_Chen To keep things simple and make sure I’m not cheating, the rules are fairly strict:

  • Only daylight hours count, excluding twilight.
  • Prolonged near work outside does not count. (Brief use of navigation/communication is OK.)
  • My field of view may not be significantly restricted compared to my glasses’ size.

So there are lots of cases where I look in the distance that don’t count. Being in a car, for example, doesn’t count. Looking out of a window usually doesn’t count. (I didn’t count any cases where I looked through windows so far, but might make exceptions if there’s a glass wall in a fairly open place or something like that.)

Tracking the exact time I’m looking at the distance isn’t really feasible right now. How should I do this without constantly using some device to input what’s going on? I’m not really cancelling my whole life for the duration of the experiment, so it’s already a bit of a task to keep track. There’s also the argument that we have no reason to assume that healthy stimulus means staring at the most distant thing the whole time. So I think it’s reasonable to count outdoor sports even if they have some exercises where you look at the ground. It’s not like I can do pushups nonstop for so long that it would make a difference in the big picture.

The lux meter is something I didn’t do yet but might do depending on the outcome of this experiment. Though even then, I’d probably be content with reasonable estimates rather than strapping some makeshift device to my head. In the end, a lot of this evens out over time, as there are always some brighter and some darker periods.

@Tony87 It looks like the eyes care about (de)focus and brightness – but ultimately, we don’t know what it is exactly. If I knew for sure that this will work out well, I’d be doing a more specific experiment. It would be interesting to know if “indoor only stimulus” can work, but since we don’t even have data about eye shortening under any conditions, I doubt that there’s any data on this.


Just to add some interesting data point: most of my distance vision is behind glasses. Either looking out of windows from a room or traveling in a car. I would say about 70% of my distance “practice” come from these.
And mostly I look really far away, close to the edge of the horizon (usually not I’m the one who’s driving) or at least for several hundred meters away. I do this mostly because my eyes so far (2 reduction) get accustomed to the reduced normalized pretty fast in about 2 or 3 weeks so I don’t get too much blur challenge “close” (I mean relatively close like in 5-10m away). On the other hand I really enjoy finding details really far away, so I’m doing this not just out of necessity, but because I enjoy it.

By the way all of these means I have almost no indoor distance practice. I don’t watch TV, rarely do movies, so usually when I’m indoor and not looking outside it’s close-up for me or I don’t have meaningful blur challenge opportunity (both my home and office has relatively small distances).

Of course there are just too much variable to make any conclusion based on these, but may add something if you have more data point on your own.


Oh, my bad, I thought you could! :wink::joy::joy::joy::+1:

I’m proud of you, 5 hours in the rain - good you didn’t choose November :wink:
(You know those huuuge :golfing_man: :umbrella: :open_umbrella: ? You might need one!)

Good to know you have these straight rules set up, I wasn’t aware - and just trying to throw in everything people could throw in against this later…

Now is anyone here up to do the same experiment with indoors vision mostly/only? The question comes up fairly often :joy:

Seeing all the screen workers here like myself &halmadavid, I’m quite sure you could achieve at least something that way.

Holding my thumbs for you!


It’s probably not the glass that makes a difference, but the peripheral vision and brightness. I think that sitting right next to a glass wall, like the ones they have in modern skyscrapers, could give excellent distance stimulus.

Generally though, on improvement up to three-week time-scales, there’s always the question whether it’s from the ciliary body or shortening. Relaxing the eyes doesn’t need peripheral distance vision, but stimulus for shortening probably does. So from your description, I can’t tell clearly whether your type of stimulus will work in the long run.

I wouldn’t be surprised if this works in some rooms and not others. A dimly lit basement probably won’t do it. A corner room with glass walls, well, that wouldn’t surprise me. There’s someone on the myopia reddit who has an office with a huge window and a great view; according to the story, two people in that office improved without even trying.

BTW, I don’t think five hours of distance vision are actually required. I just don’t know what specifically can stimulate my eyes, so I’m going for overkill for now. The point is to have no false negative result: if this doesn’t work, there’s something fundamentally wrong with the theory. If it does work, this would support the fundamental theory. Either way, I will know more after the experiment.


At february I had -3.5 normalized. I will be ready to reduce to -2.75 in 1 or 2 week. So whatever I’m doing it works, but again, I’m not sure what I’m doing right :slight_smile: so I’m curious about your experiment.


Almost agree, but, there’s a but! :wink:
Reading other posts here, I rememberd factors like that daily glass of wine , that kept someone from progressing. Now I’ll go have a look at you troubleshooting post again, cause I know you’ve ruled out a lot already!
Just a reminder to not jumping to conclusions too quickly. You’re n=1, so it could still be someting else. I know you know that :wink: , but maybe interesintg for the new.