How important is bright natural sunlight for improvement?

I’ve heard a lot of horror stories of people’s gains diminishing in the winter months. The sun’s coming out again, but the weather forecast for the next two weeks is cloudy with periodic sunshine. For people with experience comparing their results with and without a lot of sun I’m wondering how your results varied.

In my mind you’ve got no sun (darkness), daytime but cloudy, and direct bright natural sunlight. In the UK we get a lot of the first two and not much of the last one. Although the consensus is that bright natural sunlight is the best, by how much is it the best by? :thinking:

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The best for what? It is definitely the best for vision, for me, as I hardly realise that I still have -1D of myopia in the right eye (forget about the left eye), when I look at anything directly lit up by the sun. But then this is also the first time that I am paying this much attention to my vision. Whether this is the best for reversing myopia is another story. I have lived in the same place, with the same sunlight (a lot more of it in the French foothills of the Pyrenees than in the UK) for the past 30 years, uncorrected, and my myopia didn’t budge. In the 32 years I lived in even sunnier southern Africa my myopia only got worse, but that was thanks to the optometrists.
I don’t think loads of bright natural sunlight is as important for vision improvement as many people make it out to be. Regularly looking into the distance regardless of light levels, attentively, is probably just as useful.
But for lots of other reasons, bright natural sunlight is a gift not to be spurned. It is one of the reasons why I moved to where I live now, after 5 years in grey (and overcrowded) Netherlands.


Whoops, changed the title to state ‘for improvement’. It’s definitely better for vision :slight_smile:

Why do you think that bright natural sunlight isn’t as important for improvement as they make it out to be? A hunch or an understanding? Natural sunlight is brilliant for vision and mood though, and nobody can fault you for getting more sun I think :sun_with_face:

Simply based on my experience, as outlined above. It took a strong mental commitment (belief, intention and attention) to get me moving, and close-up print pushing was all it needed to improve the right eye. The extra clarity I got at distance was surprising and unexpected, but now I have started clearing things at distance as well, on the assumption that this will help. But then I am an unusual case as I have done it without wearing correction, and others are likely to have very different stories.


Do you have more myopia in places where there is less sunlight throughout the year?

My vision is worse in low light conditions, for sure just as anybody. I’m not really concerned about that though, I’m interested in what will make a difference for long-term improvment. I can’t personally say my myopia has permanently gotten worse when there was less sunlight, but @Varakari has had that experience in the winter of 2018/19.

One item that comes to mind is that having bright sunlight (which does increase the distance to blur), also provides a very good (best) stimulus for the brain to remember how things should look like (brighter, more clear, better defined in any way you can think of). And once the brain stores the quality of that in the background, it will try harder to recreate that image quality in less than favorable light conditions.

I see sunlight as a “stimulus/gift that keeps on giving” after the stimulus itself goes away for a while.


There are two sides to this:

  1. Whether you need to be constantly in sunlight or natural light conditions. It’s clearly false. People in Iceland would have bigger myopia problems and as far as I know there are no bigger problems with myopia when living with less sunlight throughout the year.

  2. Whether you need some sunlight at all, that’s completely different matter. Although there are animals living in darkness with hyperopia. So I’m not sold on the concept that you need huge amount of sunlight to avoid myopia in humans as well. What purpose this would serve from biological standpoint?

Maybe this comment deserve a bit of attention as well. It would be interesting to look at each story on its own merit:

how do people measure and make decisions on changing their lens strength: environment, lighting, time of the day;
habits: do/did they change from summer to winter months?
how much worse was the sight from summer to winter?
any factors that could have contributed (illness, stress, depression, drop in vit D).

What I am thinking is that it’s easy to paint with a wide brush, instead of looking at the details. Could it be that the euphoria of experiencing improved eyesight could possibly lead us to make changes before we are truly ready for them? I could see that for myself, I personally aim for 20/20 in a room with good artificial light before making changes, to avoid the pitfalls of changing lighting environment. :blush:

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I think you’re talking about people who are not myopic or how best to avoid myopia. Most people don’t know about EM and aren’t trying to make improvements either. I’m asking about how important natrual sunlight is for making permanent improvements to vision, although I really wish I was in a positition to be talking about preventing my vision from getting worse (from a hypothetical 20/20 me)

I’m talking about the evolution of the eye. Making eye more myopic from being in low-light environment would make no sense from biology standpoint. It would make you see even worse. We know that there’re animals that hunt and live at night. They don’t have usually myopia. They have the opposite: hyperopia. I would bet rather that the lack of sunlight causes hyperopia than the other way around. And remember that causing hyperopia is reducing myopia. That’s a different side of the same coin. r/IE

I’m pretty sure the biggest problem with winter is the less outdoor time and also a large chunk of outdoor time is at total dark where most people have really bad time with auto focus (I think many even can’t). So lot of close-up stimulus and not enough distance stimulus.

Bright sunlight and high contrast helps with autofocus, which provides the positive stimulus. Also it gives superior vision which makes people happy and more enthusiastic about the process :slight_smile: Compared to do autofocus at night where you don’t see sh*t and with autofocus you just see a bit more sh*t :slight_smile:


Interesting, I’m getting the impression that clouded days are actually not a problem at all from this! Totally different to my thoughts before which are going ‘sunny days are where the true good improvements are, you should bother a lot less on cloudy days’.

I agree with Hannie based on my first winter EM experience. No degradation this winter only a slight improvement

I actually like cloudy days for practicing active focus because if it’s too sunny I’m squinting and can’t keep my eyes open. Cloudy but otherwise bright times are a good compromise between too little light to see and squinting in bright sunshine


Yeah I much prefer doing AF on cloudy days too! To be honest I’d go out even more on those days if I knew for certain there was no difference in improvement. This thread only exists because I saw that study where they put chickens into three different groups based on light levels, no light, mild light, sunlight, and found the largest axial change in the sunlight group. Might be overthinking it though, and I haven’t read the study closely enough to see the exact light levels used for each group etc :see_no_evil:

I notice looking into a cloudy sky seems to make my eyes water (ciliary release?) most easily.

But Sunshine, almost always makes me high.

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I don’t think it matters that much what level of light is. I’m only thinking that it would be stupid to cause hyperopia from light and myopia from darkness from evolution standpoint. Everything that lives at night would perish. It’s probable that light has some importance to this but it’s not the only aspect.

In my opinion the only thing matters is active focus. If you can do that in cloudy days at night, whatever, you will improve. It’s just a bright sunny day spent outside doing things which needs distance vision promotes AF and make it easy to do. While indoor with bad lights or total dark inside / outside makes you focus close and makes AF much-much harder (even impossible if you’re not good enough with them). Of course cloudy days are somewhere in between and for some (just as @Lajos says and if I remember @Ursa and maybe @Varakari also had same experience) even promote AF more than bright days.


Yeah I can’t say this is proof but as David said it’s the amount of AF that matters and the success of it not the sunlight I think. And Varakaris experiment where he spent 5 hours outside every day for months with no noticeable gain also indicates that it’s not really directly about the light levels

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