Friday, 30 November 2012

Abuse, neglect of a two teenagers with visual needs, or dyslexic?


A couple of days ago, I worked with two teenagers who had dropped out (been dropped out) of the education system but were being pulled back in by a forward looking FE college.

Both young people had simple visual problems which had been overlooked although that is a simplification.

One, the guy, had the following problems. 
  •  One eye being short sighted with an astigmastism,and the other normal.
      • leading to very easy distraction

  • A need to turn his head sideways to look at you without severe discomfort in his left eye.( it turned.)
    • because of the uncorrected focussing problem.

  • Because of this people thinking that he was not looking at them when he was spoken to.
      • The ' Look at me when I am talking to you!'
      • Do not look out of the window boy  
'syndromes'
In addition 
  • he needed a large font to read effectively..  font 24.

  • He was light sensitive. Bright lighting was creating reading and visual problems..possibly his pupils were not closing up enough, or it could have been a low level of melanin in the back of his eyes.


  • He needed a specific colour background to read effectively.
Now all of this is correctible. By the time the session was over he was actually reading quite well and comfortably for the first time in his life.

Over 12 years late!
He has been effectively abused by a blinkered education system,  that assumed too much, which labelled him.

Oh by the way he had been labelled as dyslexic.  Did not help him though.

We discussed what he might become now. He must have been wondering how it had taken so long to get to this point.

I was left wondering about the millions of people in the UK who had solvable problems, whose lives had been limited.


Tuesday, 27 November 2012

Over one hundred thousand exam takers in UK in need of glasses.?


Are the children  in British school wearing glasses if they need them?

The graph below shows the result of a small survey of  schools in the UK,actually in all were in England.

This is not claiming to be a scientific survey just the response of parents and teachers to the question.

How many children are in your child's class and how many are wearing glasses and what year are they in? 

The sample sizes vary from year group to year group so see this only as a starting point.  More data is needed to confirm or deny what  looks to be happening.


As would be expected, the % of children wearing glasses goes up gradually from year 1 as more get sent to the optician as difficulties become obvious.
Then from year 8 (second year at the senior school, the % starts to plummet down to the lowest point when they take their examinations!



This  suggests a serious problem.  Either suddenly their visual problems are being magically ‘cured’  or there is a serious problem in our schools which is ignored.  If it really does go down to 5% in year 11, then that means between 20% and 25% of our children taking their examinations are being disabled unnecessarily.

 14% of these are actually known by parents or teachers to be disabled.

So at the lowest estimate at least 72,000   and at most  150,000 of our children taking examinations this year.  Criminal waste.


Monday, 26 November 2012

How do you know if ‘colour will help?’


How do you know if ‘colour will help?’
In the model I have developed, it is not really a ‘colour’ which helps a person. It is the reduction in stimulation of particular cone cell types in the retina; for example the red cones.


Of course you might need a different font size before you notice any difference between them.



The graph above is for a person when their font size had been optimised already and when the screen brightness had already been optimised.
Slight changes in the red pixel brightness had a huge effect on reading performance.

If a cyan filter had been used with a person in inappropriate conditions or the wrong font size I may have not given any benefit.

So to restate.  The reasons a set of coloured filters might not have given benefit can be any one or a combination of the following.

  1. Font size wrong
  2. Ambient lighting wrong
  3. The filters took too much or too little of red, green or blue light out.


As a final point I will consider the blue component of the light.  From our experience, very few people need this reducing compared with say the red or the green.   Most people end up with a sort of ‘mucky cyan’ or a ‘mucky purple’.  What you would call a ‘colour’ something like ‘Rose’ is actually a filter which reduces the amount of green light, and slightly reduces the blue.  A ‘pink’ filter would take out a different amount of green but also a different amount of blue. 

The filter sets used were originally created to test the idea that ‘different colours’ might benefit different people. 

A computer screen is a precise instrument with which to work out/calculate what will work for a person.  It is the best medium to find out what really works.

Friday, 23 November 2012

Why does text blur? One possible reason even with the right glasses



Why does text blur? One possible reason
Text Blurring; Font size and crowding

Many people, who have difficulties when reading, experience perfectly clear text for a few seconds or a few minutes and the letters blur into each other. They then find it hard to see the text. For other people it does not actually appear to all blur but they start to see fewer and fewer letters at once, just the central ones.

When your ‘eyes’ compute the images of letters, one of the difficulties is for the system to identify where one letter ends and the next one begins.  The proximity of one line to its neighbours reduces, or masks’ the ability of the system to compute its existence. This referred to as a ‘crowding effect’. It is a well documented phenomenon of the visual system.

It may well be that this phenomenon is the basis of the blurring effects which large numbers of dyslexic and slow readers experience. 

For each person a minimum distance is needed between the letters to allow the computing of the separate images.
·         To enable the capability to read, to decode, letters and translate into them phonemes.
·         To ultimately blend phonemes and then sound and ultimately spell the word.
This minimum distance is independent of focussing. The minimum distance will vary between people just like their height varies.

So getting this right for a person is absolutely basic. If the letters are too far apart, then this will lead to parts of words or subsequent words being focussed on the retina away from the centre of the fovea to part of the retina where the cone size is much larger and they are at much lower concentrations, increasing the need for more fixations per sentence. This would limit/reduce reading speed. It can also lead to a difficulty in identifying where one word ends and the next begins essential in subconscious control of eye movement.

The first indication of the importance of this letter separation was when Arnold Wilkins announced to me that he ‘had solved dyslexia, you just put the letters further apart!’



This was back in 1998!  It was rather a simplistic statement, but it had great significance.
In Microsoft Word 97, it was easy to increase the character spacing.  Arnold had tried this, I had tried it and a lot of the slower readers did find it easier.

You could argue that a lot of the reason for some fonts being easier to read for some people is really about letter spacing…..The copied lines of text are all in the same font size .

being easier is really about letter spacing…………………..    arial narrow
being easier is really about letter spacing…………………..    Calibri
being easier is really about letter spacing…………………..    Arial
being easier is really about letter spacing…………comic sans
… As well as about the effects of kerning


Unfortunately you cannot do this with a printed book, and it is only some people who find it much easier.
Other variables appear to affect the processing of the edges allowing discrimination between the edges, the ability to separate the letters.  We need to consider possible mechanisms for this.

The data is collected by the eyes oscillating slightly, with cone cells being intermittently stimulated and not being stimulated.   The blurring, fuzzing effects are often only after a few seconds or minutes of reading, suggesting a system with a time/processing component. If the letters are further apart, they do not seem to ‘interfere ‘with each other even after the normal experienced time period.
That could be because the system is not degrading any more or it can keep up.

When the optimal viewing conditions are identified, the subject reports a ‘crisper looking text’ no blurring at default letter spacing.
So what mechanisms might be responsible?
·         The whole process depends on the management of the muscle fibres that create the micro movement which dynamically collects the visual data. Logically   the metrics of this movement must be used in computing the edges,

Of course for the most academically successful usually have very high reading speeds and no reading stamina problems with small fonts. They actually find increasing letter spacing really annoying; slowing them down. There is an unfortunate tendency for high achievers to assume that what is easy for them will also be easy for other people.

 The reality is of course that the majority actually need the increased font sizes and bigger spacing!  The minority are disabling the majority, unintentionally. They do not know any better.

Wednesday, 21 November 2012

Font size and biological diversity (Font size matters)


Font size and biological diversity
(Font size matters)

Font size is an interesting variable. My colleagues and I have been measuring (calculating) which font size is optimal for each student for a couple of years now. This is an essential component of the protocols we have developed and has to be worked out before we consider other factors.

Most people will think of font size in the context of reading glasses; trips to the optician and deciding which of those lines of letters you can read clearly, or in low vision problems, where a person needs a larger font because of degrading eyesight from issues such as macular degeneration, or cataracts.

Another issue is the tendency to associate larger font size with poor academic performance, low intelligence or ageing.  These associations unfortunately leave a negative feeling and resistance towards the use of large size fonts, when they may be needed by people in the main stream population.

The inverse, the attitude to the use of small fonts, is that as we progress through the levels of education, the texts we have to encounter get increasingly smaller. In higher education there is an assumption that intelligent people can read small fonts. The decision makers (academically successful usually) in society tend to find small fonts easy. This use of small fonts, in itself of course as acts a ‘font ceiling’, restricting access to the higher levels of education to those who can cope with the small font sizes. 

Into this set of prejudices and assumptions appears the issue of wearing glasses. Too often, people assume that ‘the correct pair of glasses will enable a person to read small text. For a young person you can extrapolate this to the situation many schoolchildren find themselves in.

·        They go to an optician because of difficulties they experience with their eyes when they are reading,
  • ·        get a pair of glasses,
  • ·        go back into class
  • ·        Find that they still have problems, often still very severe when they try to read.

They then have two choices.

  1.   Carry on wearing them and get called ‘stupid’ because they still find reading slow, difficult and possibly painful.
  2. Stop wearing them, and get told off because ‘if you had your glasses you would be able to read’. The teachers regarding them and often making it quite clear, that they believe the child is ‘lazy’, ‘uncooperative’ not interested in learning and probably a trouble maker.

  3. But a bigger font size might be all they need!



What I will do now is to try and look at the issues of ‘size’ diversity in the human visual system and start the consideration how this diversity could impact on the ‘font size needs’ of the population.

I will ignore, focussing, assuming that an optician has ensured that the physics of focussing has been dealt with. If the person needs glasses they have them (unfortunately this is often not true).

Physical size/dimension variations between people.

The retina.

The light sensitive cells at the back of the eye are arranged in a hexagonal arrangement (like honey comb).  There are two types.
a.     Rod cells... tiny cells used for night vision. Not used in reading.
b.     Cone cells. larger cells used in reading
c.      This picture shows a part of a person’s retina. The red and green cells are the main ones mainly involved in collecting the image when reading. The blue cells have a role, but there are very few of them and probably mainly concerned with getting the image of the word at the fovea.
d.     Notice that the ratio of red to green cells is unequal and they are clumped. This distribution is thought to be controlled by a similar mechanism to that controlling the stripes on a Tiger. Each person is different.



The cone cells at the centre are smaller than those at the edge and packed very closely.

Right at the centre (the fovea) they are extremely small... There are no rod shaped cells here. Actually the cone cells here are so small they are similar in size to the tiny rod cells.

The diameter of the cone cells and ‘proximity’ or tightness of packing is one important variable which controls how ‘coarse’ the image will be.  . The smaller the cone cells and more closely packed, the more detail.

A bit like the number of megapixels in a digital camera;
The more the better.

The fovea itself, with its tiny close packed cone cells, at the centre of the retina, is the reason why the eyes move quickly from object to object in a visual scene.
In the rest of the retina the cone cells are much larger,  and further apart from each other (more numerous rod cells in between them), getting larger towards the edge of the retina.

The data from the each foveal cone cells is treated independently whereas the data from the rest is processed in groups.

1)   So the way they are wired, the size of the groups of cells, together can vary from person to person.

2)   The size of the cone cells in the centre of the fovea can vary from person to person.

3)   The width of the fovea itself (the zone of small cone cells in the middle of the retina.

4)   The size of the cone cells as we move to the edge of the retina.

5)   The ratio of red to green cells varies dramatically from person to person. Some people have many times as many red as green and vice versa.
If we could give a numerical value to each of the five ‘size variables’ above we can see that there is a dramatic range of combinations in design and in a way the number of ‘megapixels in your cameras’...
For example if we consider the width of the Fovea, the central area of small close packed red and green cone cells.

If a person’s fovea is smaller than the average,
 then the smaller fovea will
a.    ‘Process’ fewer letters per fixation.

b.    More pictures will be needed to get through a sentence. Each ‘picture takes about the same time, about a third of a second.

c.    It will take longer to get through the sentence.

d.   Working memory will be compromised.

Beginnings of sentences may well be forgotten by the time the person has taken enough photographs to get to the end.

There is also what you may call a double whammy here. It is thought that if you have developed a smaller fovea then the cone cells in your fovea will be bigger than for those people with a bigger fovea! 

Eye movement during picture taking

An additional complication is that if the eyes are absolutely steady during a fixation then they stop working completely. They have to be constantly wobbling at very low amplitude so that the image is moving across the edges of the cells. It is the switching on and off of the cells which gives rise to the data that is computed by the brain to create the image. It sort of has to scan the image, the words.
This movement is a consequence of

a.   Muscle  contraction in the neck or movement of the object being viewed

b.   Changing contraction /muscle tone in the six muscles which otherwise move the object on to the fovea. The eye muscles have the job of micro movement of the image on the retina.

c.   All this muscle control is being managed by the cerebellum in the brain and feedback from the muscles themselves and feedback from the computation of the image on the retina. (A link to dyspraxia?)

The amplitude and frequency of these micro movements needs to be appropriate to the size of the cells collecting the data.  If there is a problem of muscle tone management in the eye movement muscles this will change this micro movement in terms of amplitude and possibly frequency.
Essentially all of these variables contribute to not whether you can see a word, but to how many milliseconds it will take for your system to collect enough data to identify the icons/ letter/word you are looking at and match that the phonics/sounds associated with it. That time will depend in addition on what patterns have been seen and identified before and how often they have been seen and identified in addition in the context of language, the syntax from the sequence of sounds which will affect the amount of visual data needed to identify each word.

The reading process (visual data collection and computation, in my world) requires an integrated system affected in its functioning by all these variables and most likely more.

If one is compromised, such as the contribution of head/ neck movement musculature, this is almost certain to compromise/ limit the reading process. Many people with whiplash or upper body trauma find their reading performance diminishes.

I could go on much further, but I will stop here. I hope that you can be aware then that there are considerable variations in the ‘sizes’ of the components of the visual system which influence what size of font will work best for you. Most people reading this blog will read best on around a font 12 or smaller, but in the general population it looks like over half of the people need a font greater than 14 to read fluently for long periods. If you need a bigger font copy it onto a word doc.


I think this needs a mind map!  Any offers?

I will develop these explanations further. For example what is called ‘crowding’ in the next blog.

Tuesday, 20 November 2012

Neurodiversity.-A biologist’s perspective


Neurodiversity.-A biologist’s perspective

I remember wincing as I sat in the Lecture Theatre listening to a particular lecturer referring to people as being disabled by ‘having neurodiversity’.
I would not have winced if the lecture was about the implications of neurodiversity in way we educate. The way that we ought to start out is by considering ‘mixed capability learning’ or the need to consider that a population of any animal is diverse in design.’
But it is not just about ‘neuro’ diversity; unless by that we include variation in the range and capability of our sense organs.  These are not really plastic. Their design is consequential of genetics and interaction with the environment in a ‘physical way’.
On the other hand if we are really talking about the brain in terms of the way we these days look at MRI scans and extrapolate perhaps too much from them, then we are talking very much about a ‘plastic system’ which develops with us, responsive to the design of our sense organs.  
There is one basic rule in biology. If we treat each person as a ‘system’, that system will always use its capabilities to minimise the amount of energy needed to undertake a task.
For example if the visual system is compromised in any way, then you can expect the connectivity and localised energy usage (what an MRI sort of measures) to modify to minimise effort. When we see an MRI scan then much of what we see will in reality reflect sensory limitations/ capabilities rather than (or in addition to) built in neurodiversity which is genetic in origin.
There was a guy in the 1960’s who had hydrocephalus. The brain was squashed right against his skull, but with appropriate input it was able to function academically at a very high level. It was a plastic enough system to adapt to perform the tasks it was set.


If we modify, enable our sense organs to function more effectively then our brains will adjust to the new data input, if it is easier. 
My work tells me that a font 14 will enable many more people to read fluently. When I think of reading , I think about it in terms of edge detection, computing maximum visual data in each fixation, holding the edge data in memory , maximising automaticity, minimising demand on the central executive (a psychology construct) and hence liberating ‘working memory’ (another psychology construct) using the ideas developed by Baddeley at York.
 We need to consider neurodiversity in terms of maximising the number of people who can access the main means of communication….Text.   That is a visual concept. You can argue that phonological capability is reality predicated on visual performance.   But then who am I? Just a biologist.

Monday, 19 November 2012

Visual data collection problems. Evidence from Binocular eye tracking.


When you measure the way in which a fluent reader’s eyes move as they read.
And show it on a graph. This is the pattern which you see.



If you  look at the eye movements of a person who us having difficulties, sometimes but not always reporting visual stress.. This is the sort of pattern that you see. Basically you would not want to walk up the steps!



 This is actually quite a good one. In the top one the person was using far fewer photographs/ fixations to get through each line of text. This is likely to reduce demand on an already limited working memory if a person is dyslexic.
When a person has their visual stress issues dealt with . The reader at the bottom reads more like the fluent reader. 
There are case studies which I can send out. The explanations get complex.
It has often been said that the eye movements are a result of the phonological problems.
But the case studies show the reverse.  The reading fluency of the people with visual stress issues end up no different to the fluent reader population.

( sorry arial again!)
Should this be ignored?


Sunday, 18 November 2012

Dyslexia and functional literacy. Being on the edge


Dyslexia and functional literacy

My blog during ‘Children in Need’ highlighted the existence of over a million students in UK schools every day, who will not be functionally literate as adults. Scaling this for the USA we are talking about 5-6 million children in USA in schools this week.

This 20 % of the population will contain many who could be identified as Dyslexic.  This will be despite opportunity.  There has to be reasons why people find reading difficult and are unable to develop their capability.
Many will be people who should have been wearing glasses when they were young. Or they should have been wearing appropriate glasses. To be honest, I do not know about the USA but here in the UK there is no financial incentive for an optician to really look that closely at a child’s visual needs. Most teachers do not know how to look for the clues, indicators.
Many will be from families where the parent (s) found it hard work as well, so there will be few books and reading material around little academic expectation.  In many homes there is consensus that ‘books and reading does your head in’. It is not fun, not enjoyable; whatever their reading teachers tell them!
Many may have found that when they get glasses, ‘their visual stress’ problems are not solved.  They need more, possibly prisms, different font size, different ambient lighting, and different light mix bouncing off the page or coming out of the screen.
If these other issues or barriers are not removed then their reading will not develop properly, it will also affect what some people refer to as intelligence. In itself a consequence of opportunity or experience. I am unsure of what intelligence is, and what capability is. How do you differentiate between the two? Anyway which ‘intelligence’ do they mean?
A slow runner may be ridiculed or marginalised because they are slow. Being a slow runner though does not put limitations on the rest of your life. It does not cast a ‘slur’ on your brain, on your very being like being a slow reader.
Fast readers rarely have functional literacy problems. Reading speed (Oral Reading fluency in words per minute reading aloud) is an amazingly good indicator of potential academic performance.  If it takes longer to read something, a book, an exam paper, you are not likely to remember how the ideas fit together; usually it goes with misreading, guessing at words and not being able to read for long, or being a slow writer. . 
What the Dyslexic ‘condition’ tells us is that people who are slow readers can demonstrate and develop their capability but they need to learn from others the strategies to get around the reading issues.
Dyslexic people know that slow reading or functional literacy problems do not have anything to do with intelligence. The two are not the same thing.
In a way those diagnosed as Dyslexic are the lucky ones. Most people who are slow readers or have functional literacy problems will be bullied by society into just accepting their place on the ‘edge’. They will be talked at, talked about, accused of being lazy, easily distracted clumsy treated as lesser beings.  The joke is that it is possible to enable people to read more effectively/
As a final point one attempt at this has been /is ‘explicit systematic phonics’. Ok one question.
·         What were the examinations results like for those in the Clackmannanshire experiment when they reached 16?  

Friday, 16 November 2012

Autism, reading and telling the time

Why does there appear to be a visual issue in autism? Many autistic people have difficulty reading a clock face but can read a digital clock. On a clock face it is possible to 'see' the time to come and the time gone by.  Not true on a digital clock you only see 'now'. giving no sense of passing time.  Attention can get fixed on a part of the visual scene making saccading around it difficult. You need to do a visual search with a clock face. To understand the emotions on a human face your eyes need to do a visual search of the human face.
Fluent reading needs controlled attention shifting as you read. Many people identified as autistic years ago turned out to be dyslexic. Many people identified as dyslexic ..........
Is there a connection ?

Lots of Children in Need

Blog Children in need
About 10 million adults in the UK are functionally Illiterate. They are unable to read official forms properly, newspapers, even medicine bottles.
Today, at school there will be  1 in 5 children who when they are adult still not be able to read properly.
That is over 1,200,000 of our children in school today
Why is this still true?
My work has been to study this for the last 28 years.   For the last 14 years, using computers to work out what is controlling how well young people and adults read. Before the computer you had to read what you were given. The clever people could cope with small fonts. The people in the lower sets, the less successful often needed big print but were still slow readers.
Using a computer to you can choose
·         your font size.
·         how bright the background is.
·         the colour of the background.
It is possible to calculate exactly what will allow people to get their maximum reading performance. I and my colleagues are working with people of all ages at Universities, colleges but rarely in schools. There are ways of precisely fitting a computer screen to your eyes. When you do you will read more efficiently, faster, more fluently.
Having to use one size of font in examinations, and in printed material disables millions of people in this country and elsewhere.
If in the Olympics everyone had to run in size 8 shoes, different people would win. It would be a stupid rule., The same for reading, one size does NOT fit all..
From our data (over 12,000 people) we think around 4000000 (4 million) of the children in school today would read and write more easily on grey paper
Now that is an easy one. It would cost nothing!
 It can be even better but that might cost a little bit, but nothing compared to how much our children and adults lose out. Also we spend millions and millions of pounds on probably unnecessary reading support in schools at the moment. An example of further improvement is below. 

The same text is printed on a cyan background,and a magenta background ,






To find out more read the rest of the Blog. Click at the top and Join it and take part. If you found one of the  colours useful/easier  or your children ask them to have a go. Listen to them. This can be so easily dealt with on a computer. 
The cost to this country is minimal virtually free. The cost to your child of not doing it could be many thousands of pounds in lost opportunities. Please take part in making things better for millions and probably yourself.

As a final point around 25%  of our school children should be wearing spectacles. In a study I have done recently it is more like 11% 1 That means around  14% ( over 1,000,000) are in school today unable to properly see books, exam papers or board properly using an old technology. We need our schools to be glasses friendly.

(please retweet the tweet)




















Thursday, 15 November 2012

Short sight, fine motor skills and Phonological development Yesterday I worked with a student who was extremely short sighted. She had glasses on which were very strong. The optician had told her that she needed to wear them all the time. When I checked her ‘near point’, how close she could hold a book with her glasses on, this was about 20 centimetres, however anything over 40 cms away became very blurry, out of focus. Without her glasses the near point was less than 10 cms. She would never have been able to focus on writing for long. If she could at all, she would most likely have found it very painful, especially between her eyes (Aesthenopia). If she tried to write, placing her hand between eyes and page would have definitely put it out of focus. Essentially without glasses, before the age of 10 years, her vision had been so poor that she would not have been able to see let alone decode or blend sounds. From then on she was able to see what was on a page, see her own handwriting. As such she should, one would expect, have been able to develop fine motor skills in her writing, with good hand-eye coordination. But there was another twist. A short series of tests suggests that she cannot actually see the words clearly, with her glasses until the font size is 48; not yet considering colour background, This Blog has been published in Font 14. I shall copy a block at the end into font 48 for your easy comparison, At font 12 reading was extremely slow, and decoding was so poor you might mistake it for dyslexia. At font 48 it went up to 154 wpm! This is not rocket science! It might seem strange but it is a simple concept. One student at a university needed a font 35, no colour, no glasses needed. A big computer screen though! Yesterday’s student, with her glasses, could still not see a blackboard to read. She has always had to copy other people and get into trouble for doing it. Becoming marginalised. To see her writing, it needed to be large. Not fitting on the lined paper. Small writing would be hard for her to see and give rise to poor feedback from eyes to the muscles controlling hand movement. More marginalisation. The system is stacked against people with big or scruffy looking writing. It is associated with low intelligence in the world of education. Font 48 To see her writing, it needed to be large. Not fitting on the lined paper. Small writing would be hard for her to see and give rise to poor feedback from eyes to the muscles controlling hand movement. More marginalisation. The system is stacked against people with big or scruffy looking writing. It is associated with low intelligence in the world of education.


Short sight, fine motor skills and Phonological development


Yesterday I worked with a student who was extremely short sighted.  She had glasses on which were very strong. 
The optician had told her that she needed to wear them all the time.

When I checked her ‘near point’, how close she could hold a book with her glasses on, this was about 20 centimetres, however anything over 40 cms away became very blurry, out of focus.  Without her glasses the near point was less than 10 cms. She would never have been able to focus on writing for long. If she could at all, she would most likely have found it very painful, especially between her eyes (Aesthenopia).

If she tried to write, placing her hand between eyes and page would have definitely put it out of focus.

Essentially without glasses, before the age of 10 years, her vision had been so poor that she would not have been able to see let alone decode or blend sounds.
From then on she was able to see what was on a page, see her own handwriting.

As such she should, one would expect, have been able to develop fine motor skills in her writing, with good hand-eye coordination. But there was another twist.
A short series of tests suggests that she cannot actually see the words clearly, with her glasses until the font size is 48; not yet considering colour background,
This Blog has been published in Font 14. I shall copy a block at the end into font 48 for your easy comparison,

At font 12 reading was extremely slow, and decoding was so poor you might mistake it for dyslexia. At font 48 it went up to 154 wpm!

This is not rocket science! It might seem strange but it is a simple concept.  One student at a university needed a font 35, no colour, no glasses needed. A big computer screen though!

Yesterday’s student, with her glasses, could still not see a blackboard to read.  She has always had to copy other people and get into trouble for doing it. Becoming marginalised.

To see her writing, it needed to be large. Not fitting on the lined paper. Small writing would be hard for her to see and give rise to poor feedback from eyes to the muscles controlling hand movement.
More marginalisation. The system is stacked against people with big or scruffy looking writing. It is associated with low intelligence in the world of education.

Font 48
To see her writing, it needed to be large. Not fitting on the lined paper. Small writing would be hard for her to see and give rise to poor feedback from eyes to the muscles controlling hand movement.
More marginalisation. The system is stacked against people with big or scruffy looking writing. It is associated with low intelligence in the world of education.


Tuesday, 13 November 2012

A possible mechanism for the effect of colour on reading performance


Introduction to a likely mechanism for the colour background settings effect on reading from a computer or the effect of colour on reading performance.

(This is a simplified version and ought to lead to further questions)

Last night I was trying to assist a student on Skype and realised that an attempt at explaining the mechanism might be useful.

When we read the image is focussed on the retina with the centre of attention (the first few letters of the word) centred on the middle of the fovea (the most ‘accurate’ part of the retina)

  1. The fovea only responds to red and green light. 
  2. How well the light from the image of this first group of letters, is focussed on this central patch of cells, will affect how many milliseconds it takes to ‘compute the image’ which will allow us to identify the letters /word.
  3. The eyes are held sort of steady (not totally) for around a third of a second.
  4. While it is being held steady, pigment molecules are capturing bits of light (photons) in each of the cone cells.
  5. The ‘red’ sensitive cone cells are collecting lower frequency (longer wavelength/lower energy) photons than the ‘green’ sensitive cone cells.
  6. Every time a pigment molecule catches a photon it releases an electron.
  7. These electrons are what really give rise to our vision, our reading. These bits of data contribute to the computing the image and ultimately reading.


When a pigment molecule has released an electron, it twists out of shape and is no longer able to catch another photon.

 It can only do that again if it leaves the cone cell, travels into another cell, which actually surrounds the bit of the cone cell where the active pigment is held. In this second cell it has the electron replaced and twists back into the shape which can catch another electron.


This ‘recharged’ pigment molecule then has to travel back to the cone cell it came from and once again catch a photon and allow vision to ‘continue’.

 If the recharging/ retwisting process cannot keep up with the photon catching, then the cone cells will become less good at catching light and will reduce their ability to work. Images will become fuzzier, less clear or take longer to compute. Reading would be slower or not possible and the system will fail.

In normal visual activity,( reading is not normal in terms of evolution!) the eyes wander around the visual scene, in a series of saccades( fast movements)  and fixations ( nearly steady picture taking) allowing changing ratios of red and green light to hit the cones allowing them to keep up, maintain sufficient concentration of working pigment molecules.

In reading on a white background the eyes are constantly bombarded with large amounts of equally intensive ‘red’ and ‘green’ photons.
If the green catching cells or the red catching cells cannot keep up a high enough concentration of working pigment then the system is compromised and will need rest periods to catch up.

In addition to computing the image the data from the cone cells is the basis of the control of the muscles, moving and holding the eyes on target, keeping the eyes working together and landing at the right place for the next ‘picture’. If this system is compromised then the muscles will be instructed incorrectly, land the eyes pointing at the wrong, or conflicting parts of the text. Giving rise to incorrect word identification and changing the perception of word sequences and compromise spelling /word automaticity development

People vary dramatically in the numbers ratio of the red and green cone cells in their foveas and also vary in the concentration of working pigment molecules in each cell.
Changing the ratio of red: green pixel brightness on the computer screen background will directly impact on the efficiency of this system.

It is not possible to work out the correct ‘colour’ using paper. Although you can find out if someone definitely is affected. It is very likely that you will get a false negative.
I will deal with blue cones separately.



Monday, 12 November 2012

Checking to see if someone has a visual problem that is affecting their reading/writing


Checking to see if someone has a visual problem that is affecting their reading/writing


( note I am not an optician, This is a biologists view of the issue)

If you are trying to help yourself or someone else to understand if they have an unresolved but resolvable visual problem which can make your dyslexia seem worse, or perhaps be the root cause
Then try the following.

 Does the person need glasses?
1.     Hold a pen in front of one eye and close the other. Start with the pen about 10 cm in front of the open eye.
a.     Move the pen slowly back and forth
b.     If it is out of focus and
                                                             i.      Gets clearer then less clear as you move it to arms length, then… You have a short sight problem.
                                                           ii.      If it gets clearer then stays clear, then…ok.
                                                        iii.      If it stays out of focus even when your arm is outstretched, then…. the eye is probably longsighted.
2.     Try the other eye. Same questions.

3.     If the two eyes are different,  for example .one long sighted and one short sighted then you will probably  suppress one ( and get easily distracted) when reading.


This could result in an eye turning sideways and getting a pain around one eye, after a period of reading.

4.     The other possibility is an astigmatism in one or both eyes. Quite common but often not corrected if in one eye only.

An astigmatism is slightly more difficult but not really hard to identify.

a.     Draw a large capital L on a page. About 5 cm tall and wide.

b.     Hold it in front of one eye (the other eye closed) at the closest point at which the eye was focussed.

c.      If the vertical or the horizontal is fuzzy and the other is sharp then you have an eye ball with an uncorrected astigmatism.

d.     Swap eyes and test the other.

If uncorrected with glasses then an astigmatism will slow down data collection from that eye. If one eye is worse then the eye will be suppressed and may turn to one side, cause eye aches and reduce reading stamina.

How will this affect dyslexia in that poor visual data collection will make extra demands on already limited working memory and make the situation unnecessarily / avoidably worse.
Also if the reading is slower you have to hold the ideas/images in memory for longer time periods which will stress working memory which can be considered as having a time limit as well as a capacity limit. So the beginning of the sentence has ‘disappeared before you get to the end of it.

5.     If both eyes very short-sighted thus can be linked with the eyes finding it hard to ‘turn in’ to prevent a sense of double-vision.
This will lead to the book being needed to be gradually moved away from the face until it gets out of focus. Often short-sighted people are very fast readers but only in short time bursts with lots of rests/gaps needed.

6.     If an eye is turning out for some reason, the head is often turned sideways, or it is accompanied by head -shaking/fidgeting/..

Even if you have glasses, you may be suspicious of whether they are correct. Following the above checks with your glasses on can help you in deciding what to do next.
If you have problems then go back to the opticians?