
Dyslexia: scientists claim cause of condition may lie in the eyes - samwillis
https://www.theguardian.com/society/2017/oct/18/dyslexia-scientists-claim-cause-of-condition-may-lie-in-the-eyes
======
slg
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.

~~~
jdietrich
>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.

~~~
timthelion
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!"

~~~
LaikaF
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.

~~~
timthelion
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](https://www.ncbi.nlm.nih.gov/pubmed/15877307)
[2] [https://www.mentalhelp.net/blogs/the-difference-between-
grie...](https://www.mentalhelp.net/blogs/the-difference-between-grief-and-
depression-the-dsm-v/)

------
crispweed
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..

~~~
smallnamespace
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...](http://www.independent.ie/irish-news/eye-patch-therapy-a-boost-for-
dyslexics-26125664.html)

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.

~~~
zwegner
> 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.

~~~
timthelion
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.

------
jlebrech
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.

~~~
lawlessone
You should probably see a doctor that sounds more serious.

------
pavement

      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.

~~~
twobyfour
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?

~~~
to3m
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)

------
totallynotcool
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](https://opendyslexic.org)

------
brainpool
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.

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tomahunt
I think this is the link to the original paper

[http://rspb.royalsocietypublishing.org/content/284/1865/2017...](http://rspb.royalsocietypublishing.org/content/284/1865/20171380)

~~~
crispweed
obligatory sci-hub link:

[http://sci-hub.io/10.1098/rspb.2017.1380](http://sci-
hub.io/10.1098/rspb.2017.1380)

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

~~~
apk-d
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_.

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

------
Myrmornis
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](http://sci-
hub.io/10.1098/rspb.2017.1380)

~~~
lustig
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".

~~~
Myrmornis
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?

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

~~~
sulam
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.

