Dyslexia: scientists claim cause of condition may lie in the eyes | Hacker News Reader

Dyslexia: scientists claim cause of condition may lie in the eyes

theguardian.com

113 pointssamwillis55 comments

It is worth noting that there likely isn't going to be a single cure for dyslexia in a similar way that there won't be a single cure for cancer. Dyslexia is really a collection of disorders that are grouped together because they share common symptoms but not necessarily common causes.

It sounds like this could help the stereotypical "see letters backwards" type of dyslexia. However there are numerous forms of dyslexia that have nothing to do with inverted images or difficulty identifying letters. For example, many dyslexics are able to write code or do math without the symptoms they might experience when reading/writing prose. That wouldn't be the case if the problem was based on vision.

>Dyslexia is really a collection of disorders

It's a practically meaningless catch-all, because the only useful definition is "bad at reading". The DSM5 politely declines to offer any diagnostic criteria. The only treatment that consistently beats placebo is reading practice; dyslexic students improve at about the same rate as non-dyslexic students after intensive reading practice. By the logic we use to diagnose dyslexia, I have countless developmental disorders, by simple merit of being bad at lots of things.

It's entirely plausible that specific but as yet unknown developmental disorders have been lumped in to the classification of dyslexia, but dyslexia itself is a politically convenient label rather than an evidence-based disorder.

I agree. I also think that autism spectrum disorder is a meaningless catch all. But I further believe that these catch alls are harmful and should not be used. When I was in school I read a lot of papers on autism, and I found that almost all studies found that there is no general biological cause for autism, but there were always outliers. Some 20% of autism sufferers, for example, have significantly raised serotonin. I think, that rather than concluding in study after study that, "though some subjects showed signs of raised serotonin, this was not found to be a reliable indicator of autism". We really should have created a new disorder "speech delay with elevated serotonin disorder". And started studying that as a separate dissorder. Maybe we would have gotten somewhere. But instead, the US spent millions, perhaps billions of dollars trying to figure out the one and only reason why some people can't walk. "Oh no, it can't be because they don't have legs, 90% of people who can't walk DO have legs!"

I think depression has the same problem. While I'm aware there are several types there's no really no guarantee for success for any particular medication or treatment for every case.

Yes, but with depression the subtypes are recognized by medicine. For example, it short allele[1] is a recognized cause of depression, as is loss triggered depression[2]. And there is fruitfull research on the subtypes. When I am feeling paranoid and cynical, I go as far as to think that the reason for not having split up the autistic spectrum, as has been done with depression, long ago is that there is a lot of funding ear marked specifically for "autism" which would go away if you started actually breaking out the real causes.

[1] https://www.ncbi.nlm.nih.gov/pubmed/15877307 [2] https://www.mentalhelp.net/blogs/the-difference-between-grie...

If I'm not mistaken, this is true for most of the psychiatric disorders.

Since we are yet unable to figure out the exact causes, and distinguish between variants, we group them by the appearance.

> isn't going to be a single cure for dyslexia

Except not forcing children to learn to read too soon. In the 49 years since the Sudbury Valley school was open, not a single case of dyslexia was diagnosed. Because nobody was forced to learn to read, a few even not learning to read until their mid teens.

Dyslexia is just one more problem of the "one size fits all" education system. Some people need to learn at a very different pace or order to learn properly without future difficulties.

Is forcing children to eat their vegetables, take regular baths, and go to bed on time an example of "one size fits all" parenting? I find it very difficult to believe that learning to read later in life won't adversely affect your maximum reading proficiency later in life, a very concerning "future difficulty" as it is the most basic possible skill required to function in society after learning to speak. I don't think either that it makes sense to give children a choice in the specific matter of whether or not they should be instructed in this skill that is so critical to their development and usefulness to society - they are by definition the least experienced and informed about the consequences of their decisions. That's not to say I don't think kids should have a choice in anything, just that part of raising children involves not letting them make choices that significantly and adversely affect their future.

> Is forcing children to eat their vegetables, take regular baths, and go to bed on time an example of "one size fits all" parenting?

Each parent has a different style, sometimes very different from one to the neighbor. For good or bad, there's no official manual on being a parent. On the other side every child has to learn every item of a bunch of subjects at each specific age.

> I find it very difficult to believe that learning to read later in life won't adversely affect your maximum reading proficiency later in life.

All Sudbury Valley School students have excellent SAT scores. Also, children of Finland which have the highest PISA score in the world don't learn to read until a few years later than in other places of the world.

> it is the most basic possible skill required to function in society after learning to speak

Maybe recognizing e.g. subtle differences in dense shapes is more important. Or basic things like remembering left and right. Things one shouldn't rush. Things children learn by playing. Reading depends heavily on those.

> I don't think either that it makes sense to give children a choice in the specific matter of whether or not they should be instructed in this skill that is so critical to their development and usefulness to society

Why not? You forget that children _are_ social, even more so in an environment like SVS where they have voice and vote to decide on school matters. Children are very curious and _want_ to learn stuff. As I said, all students have very good SAT scores. Also they're regarded as having very good social skills and tend to be very successful. Is there any better measure of the outcome?

> they are by definition the least experienced and informed about the consequences of their decisions

And the best course of action is not giving them the exposure to gain experience?

SVS is not just "children do whatever they want all day". There are rules. Made and voted by all children. Most people don't have that kind of social interaction until much later in life. Instead they get bullies. Or they become bullies.

> That's not to say I don't think kids should have a choice in anything, just that part of raising children involves not letting them make choices that significantly and adversely affect their future.

Read more about SVS, or read the work of John Taylor Gatto. You may rethink what kind of choices are adversely affecting their future.

Do you have any evidence for what you are suggesting? A simple Google search reveals several questionable looking sites repeating the lack of dyslexia in Sudbury Schools, but there is never a source cited for this factoid. This sounds like a bunch of new age pseudoscience.

The sources are books published by Sudbury Valley Press. I don't have any source other than that one. However this fact hasn't been disputed by neither former students or outsiders, from SVS or other schools of the same model; so I'm very inclined to believe them.

Note that dyslexia seem to affect about 10% of the population independently of culture, wealth or social status, so it's more striking that there was not a single former student that said "I had/have dyslexia" or similar.

The fact that this claim hasn't been verified by an external source makes me rather dubious. Most people with dyslexia are diagnosed when they fall behind their peers in learning to read. In a learning environment in which students have no real peers there is no measuring stick to fall behind. Any student who struggles learning to read is probably categorized as "learning at their own pace" rather than being diagnosed with dyslexia. That doesn't mean the student doesn't have a problem. The school is probably just unintentionally masking the issue with their teaching style.

I would be curious to see someone test a collection of adults who graduated from the school and to see whether they show signs of dyslexia.

Fair enough. I don't see this "masking" as an issue, though. I'm curious too about signs of dyslexia in adulthood. I would bet that adult SVS dyslexics exist but are better adapted around the issue.

It is certainly possible that those adult dyslexics are better at handling their disorder. That would be a pretty strong point in support of the Sudbury Valley School. However that is not the point the school or you made. You both made a harder to believe claim that none of their students even had the disorder which strains credibility and makes me doubt the first point.

I've never claimed they didn't have dyslexia. I said they weren't diagnosed. And that they all have good SAT scores, without the need to diagnose and treat such learning disabilities.

You don't have to force them if the teaching is competent. It doesn't have to be a painful experience.

It doesn't have to be a painful experience for it to be forced. I mean "forced" in the sense that they have no option but to learn at a specific age. And some children are just not ready for that. They need to play more before taking that challenge. Many develop aversion to reading or to math, even if they don't have that much difficulty.

right, lots of children with SLI later go on to be diagnosed with Dyslexia, I doubt language learning problems are related to the eyes.

It can't be as simple as this appears to make out, right? Otherwise, it seems like you could just close one eye while reading..

Eye patches have apparently been tried over a decade ago with some success -- here's a reference from around 2000:

http://www.independent.ie/irish-news/eye-patch-therapy-a-boo...

The difference is now we have a strong hint as to why they work.

I would expect that the social stigma would severely limit uptake in school though, which is why this isn't standard today -- kids can be rather vicious when they pick up on any hint of difference or weakness.

> I would expect that the social stigma would severely limit uptake in school though, which is why this isn't standard today -- kids can be rather vicious when they pick up on any hint of difference or weakness.

Random idea--what about a completely opaque contact lens, with an image of an iris/pupil on the outside, customized for the person's eye color? It would likely be noticeable up close, but could take away a lot of this social stigma.

Better yet, would be to simply have tinted contact lenses, so that the eyes wouldn't be "identical" but they would still give 3D vision.

Note that eye patches are already being commonly used in that age group for treating amblyopia

If it were a mechanical system, perhaps. But biology suggests that visual experiences will shape the way neurons connect during the brain's development...I hate computer analogies but consider all previous visual experiences as the training corpus for the brain's neural network. The response to a particular stimulus from one eye could readily evoke a response to that triggered by two eyes. The evidence is that people can usually read with one eye closed, under variable lighting conditions, partially obscured text, and wrds mssng vwls...though sometimes #/w is considered a vowel.

At 10% incidence of dyslexia, wouldn't it be possible to survey whether people blind in one eye for a long period of time or from birth have a lower rate of dyslexia?

That's a great idea, as long as there's no common bias driving both factors.

Although I suspect blind-in-one-eye will be primarily due to accidents, so that hopefully isn't correlated with dyslexia.

10%???

Quoted from the linked article:

> About 700 million people worldwide are known to have from dyslexia – about one in 10 of the global population.

Could the linked article please stand up and give us some reference for this ridiculous claim?

> Dyslexia is the most common learning disability and occurs in all areas of the world.[3][11] It affects 3–7% of the population,[3][6] however, up to 20% may have some degree of symptoms.[12]

https://en.wikipedia.org/wiki/Dyslexia

> I hate computer analogies ... neural network.

Isn't this a biological analogy?

He's already talking about a biological phenomenon, and describing it using an analogy to machine learning neural nets, so the analogy is not biological.

>an analogy to machine learning neural nets, so the analogy is not biological.

Except that "neural nets" are only "neural" by a (biological) analogy to neurons.

So he is describing a biological phenomemon by comparison to a a type of machine learning which is itself described by the very same biological phenomenon he's trying to describe.

(nothing personal)

This is why I hate them.

They only hold up at the level of analogy.

I am somewhat dyslexic. I especially remember having trouble with switching the "b" and "d" when I was very young. At some point (age 10 or so) I developed a lazy eye. I can't help wondering if this was my brain's way of adapting to this problem of matching patterns in the receivers of both eyes.

At times I have tried using a single contact lense for my lazy eye, but it causes headaches so I gave up on that.

> if this was my brain's way of adapting to this problem

Probably no. It's normal for a certain period of child development.

Maybe several Unis should attempt studies with diagnosed dyslexics and controls where they attempt to read text with an eye patch?

I become temporarily dyslexic when I have a migraine, it's just after the blurred vision stage.

I have trouble pronouncing letters, the sounds they make are jumbled up when I read.

It feels like dyslexia to me but I wouldn't know for sure.

You should probably see a doctor that sounds more serious.

  In people with the condition, the 
  cells were arranged in matching 
  patterns in both eyes, which may 
  be to blame for confusing the brain 
  by producing “mirror” images.

I mean, geeze. I’m kind of flabberghasted reading that.

Wow. Weird. Of all the things. A rare moment when symmetry in the human body turns out to be a bad thing. I guess if it was going to a problem, optics would be the rational place where that sort of issue to seems to crop up.

This feels like a scenario where something is so weird and surprising that it is almost certainly incorrect. Amazingly weird reasons are almost never the reason.

Why would this be a problem for reading but not for every single other freaking task where both eyes look at and identify the same object?

3 random guesses:

- most objects are larger than letters

- the details of most objects are less relevant than with lettering

- you can spend more time recognising each thing, whatever it is, without slowing yourself down so much that the task becomes intractable (when reading, you have to recognise, and correctly, a lot of letters per minute)

When I have to prepare a speech or section of reading for memorization I, more often than not, write/print it using OpenDyslexic Font[1]. I've tried many fonts over the years and for what ever reason this one seems to work best for me when reading hard copies.

[1] https://opendyslexic.org

I always feel uncomfortable when researchers miss the creed ”Correlation does not imply causation”. Media jump every time - but that’s their job. In this case it is a really vague study based entirely on subjective measures and the researchers don’t pause for a moment to consider causation in subjects response to visual stimuli. There are so many shortcomings to this, mostly from the press. What is reported in the news regarding the “cure” for dyslexia is base on what 1 of the 30 subjects in the study says. I am not a believer, but I encourage more research on Dyslexia. At least the experiments in this study seem easily reproducible although I don’t expect repetitions will shed much light on the cause or cure of the condition.

I think this is the link to the original paper

http://rspb.royalsocietypublishing.org/content/284/1865/2017...

obligatory sci-hub link:

http://sci-hub.io/10.1098/rspb.2017.1380

So a simple experiment would be closing one eye and compare reading?

Depends. I presume dyslexia affects learning, not merely reading - else, people would have discovered this by accident a long time ago. So the simple experiment would be to close one eye and then learn to read.

On the same note, does dyslexia appear in people with only one eye (from young age)?

Can anyone summarize the numerical results? The abstract states 30 cases and 30 controls, but what was measured, and what was the breakdown of that measurement by cases and controls?

Here's the paper. Yes I'm being lazy/incompetent, I was hoping to get the gist of the numerical results within 5 minutes and failed. Like, a table would have been nice.

http://sci-hub.io/10.1098/rspb.2017.1380

I agree, the numerical results are poorly presented.

What was measured was wether their tests can find a dominant eye in the subject or not as well as the difference in Maxwell's centroids between both eyes.

Eye dominance results:

They had two types of test for this; the sighting test and the after-image test.

For the control group they found a dominant eye in 28 of the sighting tests and 30 in the after-image tests. In the 28 cases where they found a dominant eye with both tests, the tests corresponded perfectly, i.e. if the sighting test indicated the right eye was dominant the after-imagetest also did.

For the dyslexic group the sighting test found a dominant eye for 14 subjects, and the after-image test for 3. In the 3 cases where they found a dominant eye with both tests, the results corresponded perfectly.

Maxwell's centroids result:

For the control group they showed that in 29 cases the asymmetry between the centroids was at least above 0.3 (as far as I can tell from the figures), where 0.3 means "weak asymmetry" and 0.6 means "strong asymmetry". One case was slightly above 0.2.

For the dyslexic group 27 cases had ~0.0 in the asymmetry measure. 2 above 0.3 and one slightly below 0.3.

I have generalized a bit and labeled results ranging from 0.3 to 0.5 as "above 0.3".

Thanks! It sounds like an interesting result, presumably there will be fairly rapid efforts in the field to replicate these findings. (I'm influenced by the fact that this was published in a decent journal.)

In order to have some sense of how these findings relate to the notion of "dyslexia" as used in public life in western countries we obviously need to look at how the case cohort was selected. They say:

> all encountered difficulties in reading, spelling, writing and recognizing left from right

Presumably that means that every one of the 30 had problems with all 4 of those tasks. Possibly this is a narrower definition than that used by the public / educational psychologists -- I think they often diagnose dyslexia without requiring left/right confusion as a symptom?

Should be testable- just find out wether dyselexia effect dissappears when looking with only one eye on text.

Except that because of the condition, your brain gets trained differently at recognition. Maybe it’s possible to test for this at a very young age, before the alphabet has been taught, and use the eye patch as a treatment then.

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