Conflicting theories about Visual Stress

In his comment on my (fairly) recent post on “academic arguments and anecdotal evidence”, Philip Jones referred to the conflicting views of two academics, namely Professors Arnold Wilkins and John Stein, who put forth differing theories on the neurological causes of Visual Stress. I appreciated Philip’s comment: I don’t agree with him, but it’s interesting on a site like this to hear what other people have to say.

I am not a scientist myself – I used to be a  schoolteacher, and now I run a business, and I have to admit that I very quickly feel out of my depth in scientific discussions. As I have already made clear: if a lot of people, with no axe to grind, all report a common experience (in this case that, for some people, reading through colour alleviates distortions and discomfort when reading), then for me that is more real than analysis and more analysis of data. If you fly high enough above a forest to see the whole landscape, you lose sight of the trees that make it up – but it doesn’t mean they are no longer there.

Anyway – conflicting theories. Unfortunately I haven’t got time (no, really!) to explain them at the moment, but Wilkins (Essex University) suggests that Visual Stress is caused by “Cortical Hyperexcitablility”, and Stein (Oxford) theorises that the cause is “Magnocellular deficit”. The Cortical Hyperexcitablility model proposes that the correct tint to alleviate visual stress in an individual can be one from a wide range of colours across the spectrum; the  Magnocellular Deficit model suggests that the only colours that “work” are blue and yellow.

We (Crossbow Education) sell coloured overlays – thousands of them, every year. Our records of colours selected by thousands of customers consistently show, year on year, practically the same percentage of our ten tints sold. The figures are so consistent that they have statistical significance.  By far the biggest number sold are blue and yellow, but the point is that we sell thousands of the others as well – purple, pink, green etc.Visual Stress is perceived as a syndrome (often known as “Meares-Irlen syndrome), that is a collection of signs and symptoms that are observed in, and characteristic of, a single condition. Right now I have an itch on my leg. My skin is in an irritated condition. Is it caused by my varicose vein (yes I am that old)? Am I reacting to the detergent my wife used when she washed these trousers? Do I have an insect bite? These are all real causes of an irritated skin condition, and there are many more.

Generalising very broadly, there are more than twice as many people using blue and yellow overlays that any other colour. Is it possible that there is a condition called Magnocellular Deficit, which causes the symptoms of visual stress and which is remedied by reading through yellow or blue coloured overlays, and another condition called Cortical Hyperexcitability, also causing the same symptoms, and which is remedied by reading through a wide range of colours which also includes blue and yellow?

Arnold Wilkins and John Stein are men of great intelligence and integrity, who have come to their conclusions through thorough and painstaking research. As I said, I am not a scientist; but rather than seeing their conflicting explanations as cancelling each other out – and therefore destroying the scientific validity of using coloured overlays and tinted lenses to improve reading experience – I think that they could both be right. There isn’t just one scientific reason why reading through colour appears to benefit about 20% of the population to varying degrees: there are two.

Bob Hext, 10 Feb 2015

Is Autism “Ballooning”?

I’ve just had a linked-in “discussion” drop into my inbox, starting with “In the last 20 years, Autism has ballooned across the nation and the medical community is ‘baffled’ as to why this is happening.” It wasn’t really a discussion, more of an advertising pitch, so I didn’t get involved there – but I do have a couple of thoughts on the subject.

The Recognition Curve

Firstly – and I think this is the case with a lot of Learning Differences – whether or not autism autism has actually “ballooned”, certainly the awareness of it has. We now recognise certain traits as being “on the ASD spectrum”, whereas ten years ago the same traits may have just marked someone out as being “different” without defining how. Depending to a certain extent on the policy of the Local Authority, dyslexia was in a similar place on what you might call the “recognition curve” fifteen years or so ago. And ten years ago who had even heard, for example, of Oppositional Defiant Disorder? Yet just because the condition was not on the public radar this doesn’t mean that individuals and families were any less affected by it.

Help! I Need a Label.

So as science continues to extend the boundaries of our understanding we are able to identify different conditions, and with identification comes tailored support, adaptation and in some cases treatment. Unlike in some cultures, where “Special Needs” is still stigmatised, I think we can be proud of our inclusive philosophy in the UK, and because of that I think it’s important that we see the identification of a “Special Need” as a positive guide to understanding, not as a negative label for discrimination. The better we can categorize and define our behaviour, the better we can understand and help each other.

The Bubble that’s Ballooning

Alongside all this – and here’s the other thought – I do think that society is changing in such a way that people can spend much more time in their own private “bubble” than used to be the case. There was a time when the rise of the TV dinner was deplored in some circles for its detrimental effect on family life. Those days are long gone: now a multitude of virtual worlds, digital friends, and all the worst excesses of the internet are available, literally, in the palms of our hands. The nature/nurture debate is an old one, but if we are shaped at all by our environment, isn’t it likely that the time that children can spend cut off from other people by the screen in front of them is going to cause an increase in social communication difficulties? The linguistic root of “aut” ism is “self” ism, and today’s world is surely breeding it.

Bob Hext

Academic Arguments and Anecdotal Evidence

I don’t normally get involved in the fallout from academic arguments, but on this occasion I will, because, like Mark (, I feel that this needs a response.

You can look through both ends of a portable telescope – it will either magnify what you are looking at, or make it practically disappear. It’s the same with figures. Depending on what position  you want to justify, you choose your data accordingly. So for example global warming is happening, or it isn’t. Drinking a certain amount of red wine is good for you, or it isn’t. Coloured overlays and reading rulers can make a difference to some people’s reading experience, or not. There is actually a wealth of accumulated evidence from 20 years top level academic research to say that they do, plenty of which is peer reviewed – if anybody who wants to look at it, just click on the link in the footnote below. The question is, what do you want to believe?

As one of the people responsible for the significant increase in awareness of Visual Stress over the last decade, the following (alongside the compelling scientific evidence from Essex University, Oxford University and elsewhere) is what I believe. It comes from a seven-year old girl called Maddy, and was given to me by her dyslexia tutor who is a senior professional at a highly respected teaching college:

“ …. The words look different, they won’t stay still and then I start to see ‘rivers in the text’ when I try to  concentrate on text books at my school.  Sometimes it looks like the words are almost 3D and with little lights behind them.  I try blinking a lot to get the words back into focus and then sometimes I even see colours round the text.  But then when I started to use the blue reading ruler, the “weirdness” went away …”

Ah, but there’s a problem, isn’t there? This is merely anecdotal. Maddy doesn’t exist in the cloud of figures that swirl around research like midge swarms. But she has a face, and a story; and I’m sure we could arrange for the people who said “manipulation of the visual system using colour to facilitate reading lacks scientific support” to meet her, or her tutor, if they wished. Or maybe  the American Academy for Pediatrics, Council for Children with Disabilities, American Academy of Ophthalmology, American Association for Pediatric Ophthalmology and Strabismus and the American Association of Certified Orthoptists, who concluded that “… scientific evidence does not support the efficacy of … special tinted filters or lenses in improving long term educational performance” would like to meet the little boy that Mark quoted who, when he looked at text through a blue overlay, said “Is that what you mean by a word? Can I start learning to read now?”

We designed the Eye Level Reading Ruler ten years ago now. There are thousands more stories like Maddy’s out there, of lives that have been changed during that time because “the weirdness went away”.  We hear some of them, when people have the time to write to us, but mostly they exist in the results from schools who assess all their weak readers for visual stress and see significant increases in reading levels when the overlays have been given out; or in the research project from a London University dept of psychology (over 30% increase in reading speed in some children) that wasn’t accepted for peer review because apparently 72 subjects was not enough. To you 72, even though you apparently don’t exist, you know better, and I salute you!

One of our staff sent me an amusing post a few months ago. It went something like this: “To the optimist and the pessimist: While you two were busy arguing over the glass of water, I drank it!Signed, the Opportunist”. Whatever the arguments, there is only one truth. No doubt the midges will continue to swarm. And while they do, the “weirdness” will carry on going away as more people discover how filtering out specific wavelengths of light can neutralise the pattern glare from the repeated stripes in text and put an end to the over-excitation of their visual cortex. So to everyone in that great body of anecdotal evidence, I have one thing to say: we will be here for you.

Bob Hext

Managing Director, Crossbow Education Ltd.

(Unashamed purveyors of Visual Stress Solutions.)


Footnote: Crossbow, Cerium, and I.O.O., who are the leading UK manufacturers of overlays systems, work closely with the scientific establishment to ensure that their products meet the criteria established by the research that detractors say doesn’t exist, but which can be easily found, for example, at , or read about in Arnold Wilkins’s excellent book “Reading Through Colour”. We don’t get involved with coloured lenses: we leave that to the optometrists, whose patients will have their own set of stories of life-changing freedom from Visual Stress. The instrument they use to prescribe the correct lens tint is called the Intuitive Colorimiter. It was developed at Cambridge University and funded by the Medical Research Council. Unscientific? Really?


Get A Grip!

We’re currently on the lookout for improvements to our range of pencil grips. Meanwhile here’s a quick thought for those of you who are trying to re-train the hands of children who have developed an improper pencil grip.

This idea is based on something I read on an occupational therapy site.

The child holds a little soft ball, or a piece of play dough or similar to hold with their ring and little fingers, which gives those digits something to do (as opposed to trying to wrap themselves round the pen) while the third finger, index and thumb can take control of the pencil. I thought the following could be an option if a child has a small toy figure that that they like – depending on the age of the child you can make a game of it: “Jimmy (the toy!) is going to try and grab your pencil, so you’ve got to hold him down to make sure he behaves himself!”

This is probably my shortest blog yet – hope it’s useful. If you need ready-made pencil grips we’ve got a pretty good selection at

Reflections in China 2: Time on our hands

How do you feel when a shop assistant is hovering around you, waiting for you to make your selection? I know what it does to me: I feel pressurized and intruded upon. It’s the same if we go into a restaurant, and  haven’t made up

our minds from the menu by the time the waiter comes to our table: we feel hassled and rushed into making a choice.  Maybe it’s because we have become conditioned  by supermarkets and online shopping, where nobody interrupts our deliberations or asks anything from us until we come to part with our cash, but we have reached the point we can do pretty well all of our daily trading without having to enter into communication with anybody.

The first time we ordered a la carte here (as opposed to serving ourselves at the buffet), the waiter brought the menus and just stood there quietly, a human statue. I thought: “Stop breathing down my neck! Go away and come back when I am ready!” Since I don’t speak any Chinese other than Hello and Thank you, there was nothing I could say, although I expect I made some rather disgruntled noises because he did actually wander off and come back a few minutes later. A similar thing happened when I went to buy a couple of shirts: the minute I entered the shop, I had a shadow. Fortunately we had a Chinese guy with us who was able to talk to the shadow about what I wanted, but the whole shopping experience was a communal enterprise, even down to the assistant passing her comments (via our friend) on whether the clothes suited me or not when I tried them on. So far from “I’ll have these two please. Thank you.”

I soon got used to the statue by our table, because there is always a statue; and I haven’t bought any more clothes. But I did get to reflecting a bit about the two experiences. The shop assistant was there to serve me, rather than to sell. If I’d been an hour in the shop her manner would have been the same. The waiter was just … waiting. What was different about the Chinese way?

There are a host of reasons why one culture is different from another, but I think one of the things at work here is a difference in our attitudes to time. We tend to be governed by schedules and timetables, and we can easily get under pressure to “make the most of our time”. We think of time as a commodity that we  waste if we don’t use it to produce tangible results. We can so easily spend our lives rushing from one result to the next that the weeks and months pass without us giving time to what matters most: friends, loved ones, places and things of beauty. We devote ourselves to “building with wood, hay and stubble” instead of “gold, silver and precious stones” (ie things of eternal value – the quotes are from the New Testament). Maybe the reason we ask ourselves “where did the time go?” is just that: it went in the pursuit of stuff that doesn’t last.

Here though, where civilisation is 5000 years old, there seems to be a different attitude (although whether it will survive the tide of Westernisation is another question. But that’s for the next blog.) Friendship, service and community are cherished above the “ker-ching” of a cash register having to chime every hour. Time spent achieving nothing isn’t wasted: if it isn’t given to assisting another person in the pursuit of their objectives, or just enjoying their company, it can simply be spent being at peace. We are here primarily on business, but I’m beginning to feel that I’m going to come back to the UK with something far more valuable than any deal we strike or contract we sign, and that is an increase in my store of patience.

Does this have anything to do with Dyslexia, or for that matter Visual Stress? Not a lot. Except for one thing. A problem keeping track of time is known to be a dyslexic “weakness”. We (Crossbow Education) have sand timers and even a Time Tracker in our product range. But maybe that’s not the case. Maybe the weakness is actually in our Western lifestyle, that insists on time being something that has to be tracked.

Bob Hext

Leshan,   Sichuan Province, August 2013

Note on the image:
The picture is of the Leshan Giant Buddha, who is apparently waiting for a future incarnation of the Buddha to return and bring salvation to mankind. As a Christian I’d say he’s waiting for the wrong guy, but he makes an excellent image of patience!

Reflections from China: 1

Driving on Autopilot

Who Needs Traffic Lights?

Who Needs Traffic Lights?

If you visit a new country for the first time there are always surprises: the culture, the food, the language, the way people dress, the customs and so on. Anne (my wife) and I are in China for the first time, and all of the above certainly apply. But what I want to write about here is the traffic – or more specifically, the way people drive.

We are in Szechuan province, famed for spicy food (there are some other rather “exotic” expressions of the culinary arts here that you would certainly not see alongside the Szechuan chicken in a Western Chinese restaurant, but we won’t go there at the moment), giant pandas, the Bamboo Forest where Ang Lee’s “Crouching Tiger, Hidden Dragon” was filmed, an earthquake disaster a few years ago, and the provincial capital Chengdu: one of the seats of ancient Chinese civilisation, home to 15 million people and still unheard of by many people in the West. Chengdu is our base on this trip.

We had been told that the traffic in Chengdu was terrible – completely gridlocked during rush hour periods. Actually we think that London is far worse. At least the traffic here moves slowly at its peak… But what struck us was not the volume, so much as the driving style.

In England we have the Highway Code. The Highway Code defines pretty well how to behave in any circumstance: what side of the road to drive on, who has the right of way where, how to approach a junction etc. We know where we are and what to expect, and we know what the other chap is supposed to do. How many times could the caption to a minor accident be “But I had the right of way, and he just pulled out in front of me!” A lot of the time we drive, to a degree, on autopilot.

Here though, it’s a different story. They do have road markings of some sort, but they seem to be, well, optional.  Crossing a major intersection seems to be more a matter of picking a way across the traffic rather than waiting for a gap. The scene is more reminiscent of a dodgems circuit than a crossroads. (Actually the dodgems ride is probably more ordered: “This way round” comes to mind!) And it’s accompanied by the soundtrack of a cacophony of hooters. There seems to be a single rule, and it goes a bit like this: “I want to go there, and if I hoot (not that you’ll know I’m hooting at you, but never mind I’ll hoot anyway) and head in that direction, the chances are you’ll stay out of my way!

The amazing thing it seems to work. We’ve only been here a couple of weeks, but in that time I have not heard a single screech of brakes, let alone witnessed any kind of accident. Then this morning, as we were in the back of a car and the driver was threading his way across the oncoming traffic to turn right, I had an idea: the reason these people manage to avoid accidents is because they are watching each other, instead of making assumptions. There may be no apparent adherence to much in the way of a Highway Code, but there is no autopilot either.

Has this got anything to do with dyslexia?

I’ve often heard it said by dyslexic people that they don’t drive on autopilot – they have to think about every driving decision. Anne said as we sat in the car this morning (and she was talking from experience) that she reckoned a dyslexic person wouldn’t have any trouble negotiating that crossroads, as the attention required would be no different to how they normally operate anyway. And here is where this little story has been leading: maybe we all need to learn from the dyslexic mind, as we try to negotiate the busy crossroads of our lives – better to watch out for each other than always to go by the book.

Bob Hext

Spotting the Elephant: A Tale of Two Costs

elephant in the roomThis is about taking visual stress seriously, and I’m thinking about it at the moment because this Thursday the county of Norfolk are doing just that.  Norfolk Sensory Support are holding a conference on Visual Stress, where leading  Specialist Professor Bruce Evans will be speaking, and one of our visual stress assessment packs will be given to each of the 150 schools attending.

What follows is some maths which includes estimates, approximations, extrapolations and I’m sure lots of other ations which may not be scientifically accurate but which point to  a reality which needs to be addressed. If you need to accurate measurements for the elephant in the room before acknowledging that it’s there, stop reading now; if you are happy to recognise the shape behind some rather blurred figures, carry on reading – and, if you can, pass it on.

Cost 1: not assessing for and supporting Visual Stress in school

The UK Prison population was 86,286 in Nov 2012. 50% of prisoners have a reading age of 11yrs or (much) less. There is a strong connection between illiteracy and offending. Surveys show that about 25% are dyslexic, so about 8,600  (10% – double the national statistic) probably suffer from severe Visual Stress. This is probably a conservative estimate – the figure of 8,600 is based on doubling the percentage of the population who suffer from visual stress severe enough to seriously impede reading. I have doubled it because the percentage of offenders who are dyslexic is at least double the national average.

The cost p/a of keeping one prisoner approx £45,000 (The Guardian Nov 4 2010). Therefore the annual cost of keeping 8600 visual stress sufferers in the prison population = £387,000,000 (Yes this is an oversimplification, and a number of those people would still be there if they didn’t fail at school because of illiteracy caused by visual stress; but spot the elephant nonetheless.

Cost 2: Assessing and supporting Visual Stress in every UK primary school

The cost of assessing and providing reading rulers/overlays/tinted ex books for one primary school child over one year is approx £30.00. This is based on the material cost of the products that one could reasonably expect one child to go through in a year, plus apportioning the single outlay of £50.00 for the assessment pack.  Therefore the annual cost of assessing and supporting V.S in 20,000 Primary Schools = £7,500,000.

Following this through, the possible potential saving to the taxpayer of coordinated nationwide Visual Stress intervention could be as much as £379,500,000.

Norfolk’s contribution?
150 schools is about 0.0075% of all the primary schools in the UK.
So 0.0075 % of  £387,000,000 is £2,902,500!
And of course all this is just money. You can’t measure the impact on individual lives with figures like this.

I know it’s not that simple. Not everyone with undiagnosed VS turns to crime, and people don’t just turn to crime because of illiteracy.  These figures are just an attempt to indicate something of the scale of the issue: it’s a sketch of an elephant; not a photograph. But the difference this conference will make to a lot of children’s lives is huge.

Rage against the dying of the light


Loading… (Photo credit: Matt Biddulph)

Who remembers the overhead projector?

When I was still teaching it was the pinnacle of technology in the school where I last worked. We used to hear rumours about these wonders called Smartboards in schools more budget-rich than ours, but I had never actually seen one, let alone used one in any of my lessons. So – OHP it was. And it worked, too: like moths, children were drawn to the light (actually, aren’t we all?). But what has prompted this blog is the fact that I was taken back ten years to those days at the dyslexia conference where we had an exhibition stand last Friday. The keynote speaker was a children’s author, and his impassioned plea to the gathered teachers was that they should be teaching children to love reading, rather than train them to pass phonics tests. And he was no power-point monkey: no bullet-points for his presentation. For his visuals he used an overhead projector.

I thought about his presentation- and technology – when I saw a couple of articles in the newspaper yesterday. One referred to a statement from one “expert” (I don’t know if this person had ever taught children) who said that the thousands of parents who came into schools on a voluntary basis to listen to children read were not sufficiently qualified to do the job properly; and that it should be left to trained teachers. The other was discussing the decline in standards of children’s literacy since the year 2000, when UK was about 7th in the world, to the present times where it is lower than 20th (25th in 2009, although it may have gone up a bit since then) What struck me is that the decline in standards pretty well tracks the demise of the OHP: as technology has improved, learning has diminished. And the more we measure, the more we fail. The more children drill, the less they read. Listening to a child read aloud doesn’t produce a measurable outcome that can tick an Ofsted box: what it does is give that child a sense of audience, and the opportunity to feel words and enjoy the sound of them with all the multisensory feedback that entails.

Interestingly enough, I went ot a conference on Saturday as well, and the keynote there was “beyond phonics”. Is something changing (I wrote a couple of weeks ago about the NFER recognising that children need “a variety of approaches” to learn to read)? I hope so. Because the question is –  are these two articles connected? Is the decline precisely because the light has gone out of literacy learning? Children are being taught to segment words, but not to love them . But “without Love, I am nothing…”    I very much doubt if the person who wants to withdraw the army of parent volunteers from schools would use an OHP to present her arguments.

Dylan Thomas loved words: he served them up like a gourmet dinner. The title of this article is from one of his most famous poems:

Do not go gentle into that good night
Rage, rage against the dying of the light…”

Bob Hext

Can the Hand say to the Eye: “I have no need of thee?”

Edward Jenner

Edward Jenner (Photo credit: Wikipedia) would have had the same problems…

In the original quote, (from 1 Corinthians 12: 21, in the New Testament of the Bible) the eye and the hand were the other way round, but never mind…

While I was researching an article I wrote for Special Magazine in March, I came across the following…

‘A policy statement issued by the Committee on Children with Disabilities, American Academy of Paediatrics, American Academy of Ophthalmology, and American Association for Paediatric Ophthalmology and Strabismus stats that:

“Visual problems are rarely responsible for learning difficulties. No scientific evidence exists for the efficacy of eye exercises, vision therapy, or the use of special tinted lenses in the remediation of these complex neurological conditions.” ‘

Having got over my sense of frustration at this attitude, I had to ask myself the questions: “Just what, or whose, agenda are these people on?” and “Exactly where have they been looking for evidence?”, and even “Have they seen just how much of the brain is dedicated  to visual processing?” . I’ve been meaning to post on the subject ever since.

Unless this committee’s view of learning is limited to specific cognitive processes that take place entirely outside of the visual processing centres (and of course they understand  the brain in its entirety, unlike the rest of  the human race to whom it is currently given, I believe, to understand less than 10%…), this seems like saying “If a car doesn’t work properly it’s never got anything to do with the transmission”.

What’s worrying is that committees such as this one make pronouncements that influence policy, and that simple, cost-effective interventions that will both change lives and save large amounts of money remain sidelined instead of becoming enshrined in mainstream thinking. Nobody would deny the need for evidence-based research to underpin policy, but even if the sheer weight of anecdotal evidence of many thousands of people for whom the “words stopped moving” as soon as they read through colour is insufficient, is the scientific rigour and the peer-reviewed research of the Dept of Vision Science at Essex University not enough?

I suppose it’s always going to be that way: Science waits in the car with the engine running, while the establishment is still asleep in bed. Edward Jenner would have had the same problems introducing his discovery of the smallpox vaccine, and the science of immunology…  But if anybody has any means of contacting the above committee, would they mind sending them a copy of this link to Arnold Wilkins’s web pages, “Colour in the Treatment of Visual Stress”   and ask them to PLEASE WAKE UP?

Bob Hext   June 2013.

Reading comfort, lighting levels, and what you can do.

The "beat effect" problem created wh...

80% of classrooms still use old fashioned, flickering flourescent tubes.

Classroom Lighting is often too bright
Lighting in classrooms and offices is often very bright. This is partly because the room lights are left on unnecessarily, and partly because window blinds are often not used. In a recent survey more than 35% of classrooms had lighting levels that exceeded the level at which reading starts to become uncomfortable (1000Lux). It is good practice to ensure that ceiling lights are turned off when not needed and to use the window blinds to prevent direct sunlight entering the classroom.

How you can check using a camera
To determine whether the lighting levels are appropriate, you can take a single lens reflex camera and direct it at a page of text on the desk. The lighting is at recommended levels when the exposure is appropriate for a film speed of 100 ASA, an aperture of 5.6 and a shutter speed of 1/25th. More than this and the lighting levels are unnecessarily bright.

Unhealthy Lighting
More than 80% of classrooms still have the old fashioned form of fluorescent lighting, in which the lamps flicker 100 times per second. This lighting is unhealthy: it can cause headaches and eyestrain and the flicker interferes with visual tasks.

Eliminate the Flicker
Next time the lighting in your school or office is changed make sure that the new form of high frequency electronic circuitry is used to control the lamps. This eliminates the 100 per second flicker and although the installation costs are higher, the lower running costs offset the additional installation costs in about two years. High frequency electronic circuitry can readily be obtained from conventional suppliers. Some circuitry has the additional advantage that it can enable the lighting to be dimmed.

These notes are taken from the page on lighting in Crossbow Education’s Visual Stress Assessment Pack, which contains lots of background information as well as how to conduct a test for choosing the correct coloured overlay.

An afterthought
I remember an afternoon when I was still teaching: it was a difficult, noisy class of 13-14 year olds. Someone asked if I could switch off the lights and pull down the blinds. I resisted, because I was suspicious of the motives of the person who made the request. However I acquiesced eventually. The tension leaving the room was like air escaping from a  balloon. A lot of children in that class had difficulties with reading and writing, and they were the ones, usually, who were the source of the disruptive behaviour that often occurred. If I had known then what I know now I would have switched those lights of a lot earlier, and a lot more often!

Bob Hext