Download Approaches to remediating visual stress

yes no Was this document useful for you?
   Thank you for your participation!

* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project

Document related concepts

Reciprocal teaching wikipedia , lookup

Dyslexia wikipedia , lookup

Deep dyslexia wikipedia , lookup

Approaches to Remediating Visual Stress
Melanie Jameson
This article is an exploration of the issue of Visual Stress and the varying
approaches to remediation. Which one can we believe when all claim to hold
the key to resolving symptoms and improving reading? An exploration of this
topic is followed by summaries from proponents of leading remedial approaches.
Ever since photos of bespectacled children appeared in newspapers, under the headlines
‘Tinted lenses unravel mystery of Dyslexia’, ‘Coloured cure for dyslexia!’, I have been
asking questions. Why does colour help? When doesn’t it help? Which colour is best?
How do we screen for this condition? What are the symptoms? To whom should we refer
our dyslexic students? What should we call this condition?
Tracking the phenomenon of visual stress through a series of name changes is a
challenge in itself! Named Scotopic Sensitivity Syndrome by one of the pioneers, Helen
Irlen, it then became known as Irlen Syndrome, followed by Meares-Irlen Syndrome, to
include the contribution of another researcher - Olive Meares. Both women independently
drew up a list of symptoms and advocated coloured overlays as a remedial measure
(Meares, 1980; Irlen, 1991). You may also come across the terms Colour Sensitivity and
Visual Discomfort; one specialist refers to Asfedia. The Institute of Optometry is among a
growing number of organisations that now recommend Visual Stress, and it is this term
that I shall use.
The aim of this article is to present key interventions which claim to alleviate the following
symptoms associated with reading: headaches, swirling, blurring and fading of print,
frequently losing the place and ‘glare’.
In the early days I was very aware of my position in the no-man's land between three
areas of expertise (optometry, psychology and education), none of which seemed to be
taking the lead on resolving this multi-disciplinary problem. In order to make a start, I
developed a Visual Processing Checklist, with guidance from the Institute of Optometry, in
an attempt to identify dyslexic people most likely to need specialist attention. The checklist
suggested when visual stress was a factor and indicated if there were further issues
(Jameson 1995, rev 2000).
Work on visual stress was first undertaken to help sufferers from migraine and epilepsy.
Both groups can find that certain shapes, or the effect of black print on white paper, can
form unpleasant patterns and bring on attacks. The use of tints - either coloured overlays
or tinted spectacles - seemed to prevent this hypersensitive area in the brain from
overreacting. Since some people with dyslexia also experienced a glare or other
indications of visual stress, it was logical to investigate whether colour could also assist
this group.
Another crucial factor was then flagged up: research projects in the first half of the 90s
established that there was a high correlation between dyslexia and certain vision problems
which were not picked up in standard NHS eye tests and found to be more common in
dyslexics than their peers (Evans et al, 1993). They included anomalies of
accommodation, refractive error, binocular instability, (the degree of malalignment of both
eyes may vary even during the course of a single day), uncompensated longsightedness,
irregular eye movements and poor tracking. Further work confirmed that there was a
degree of impairment in detecting visual motion and established that, at the cellular level,
the transient magnocellular visual system appeared to be deficient in about three quarters
of the dyslexic population (Eden et al,1996). ‘Pattern glare’ was a further issue: certain
patterns, including lines of print, become unpleasant to look at, causing illusions of colour,
shape and motion (Wilkins 1995).
It must be stressed that, after ocular correction or visual training (specific eye exercises),
many struggling readers will see an improvement in their ability to decipher print. For
others, colour therapy may be beneficial (Wilkins, 2003). Indications that colour therapy
may be appropriate include:
 Symptoms of visual stress / persistent eye strain despite conventional eye treatment
 Dyslexia
 Headaches or migraine in the family
 Photosensitive epilepsy
Further improvements depend on the nature of the reading matter. Difficulties are
exacerbated by small print, badly spaced text, bright white paper and text justified down
the right side of the page (this may give the impression of rivulets of white meandering
down the page). It is also much easier to keep the place when text is not right-justified.
The use of fancy fonts or busy backgrounds also produce barriers to reading (Jameson,
1998). Students are advised to copy key handouts on to tinted paper, buy tinted A4 lined
pads for writing and modify fore- and background colours on their computers.
I am not suggesting that dyslexia has a visual component in every case but rather that
visual symptoms should always be given due consideration. While assessing 300+
possible dyslexic students in FE and HE, I was struck by the numbers reporting symptoms
of visual stress. Initial use of overlays elicited the following comments from students:
"They make the text much clearer".
"They stop that wave that you see".
"They stop the letters moving about".
"They stop the glare".
It is likely that the availability of overlays leads to the risk of them being ‘prescribed’
without investigation of visual dysfunction. For that reason: A thorough eye examination
should be carried out with particular attention to the ophthalmic correlates of dyslexia
(Evans 2001). Some types of eye problems will call for the involvement of further
specialists: an Orthoptist (who specialises in the function of the eye muscles) or an
Ophthalmologist (an eye consultant, trained in medical / surgical treatment of eye
In conclusion, the very acquisition of literacy can be jeopardised if these problems are
unresolved. Conversely, the successful identification and treatment of these conditions
can lead to a dramatic improvement in reading. Handwriting, spelling, hand/eye
coordination and spatial abilities may also improve.
-------------------------------------------------------The following summary section outlines a range of approaches to intervention and
remediation in the order that I came across them; an internet reference is supplied in each
case. Some of the contributions have been slightly edited for clarity, but on the whole they
are in the practitioner’s own words. It is important to point out that not all have been
through the peer-review process nor undergone thorough controlled trials. (The first two
approaches have undergone the most rigorous evaluation.) Profs Evans and Wilkins are
now establishing a Code of Conduct for colour practitioners who sign up to evidencebased practice.
The Irlen system
In 1980, Educational Psychologist Helen Irlen discovered and categorized an array of
distortions causing reading problems, created a diagnostic testing method for identification
and treatment, and created coloured overlays, lenses, and contact lenses to mitigate
reading problems.
For the past 25 years, the Irlen Method has been the subject of numerous research
studies, there are 34 countries with Irlen Centres, over 6,000 educators use the Irlen
Method, and millions use Irlen overlays and wear Irlen Lenses. The Irlen Method improves
the brain’s ability to process visual information and eliminates distortions and visual stress.
Areas that can improve with Irlen Coloured Filters are reading fluency and comprehension;
strain, headaches, math computation, copying, reading music, sports performance, depthperception and, ultimately, motivation and self-esteem.
The Irlen Method consists of two testing sessions and annual tint checks. The testing is
conducted by Certified Irlen Screeners and Irlen Diagnosticians, trained educators and
psychologists familiar with learning and reading problems.
The MRC Intuitive Colorimeter system
Visual stress can often be removed using coloured filters, either coloured sheets of plastic
placed upon the page (coloured overlays) or coloured ophthalmic lenses worn in
spectacles. The hypothesis is that perceptual distortions occur because a spread of
excitation causes visual neurons to fire inappropriately in response to a visual stimulus.
The degree of susceptibility to distortions increases with, and reflects, the degree of
cortical hyperexcitability. Tints redistribute the excitation from a visual stimulus, avoiding
locally hyperexcitable areas.
If overlays prove beneficial, the appropriate colour is best selected using the Intuitive
Colorimeter, a device that shines coloured light onto a page of text and allows the hue and
saturation of the colour to be varied independently at constant brightness. The optimum
colour can then be selected rapidly by successive approximation. The required colour is
then made up in tinted trial lenses and assessed under natural viewing conditions. The
lenses are designed to provide the appropriate colour under white fluorescent lighting, and
to do so with as smooth a spectral transmission as possible, thus reducing the variation
from one type of lighting to another. Any necessary adjustments to the tint can be made at
the trial stage; the selected combination then forms a prescription that is sent to a
manufacturing optician for making up in spectacle lenses that incorporate any refractive
correction necessary. The patent for this system is owned by the MRC. Assessment with
the Intuitive Colorimeter is available at more than 200 optometrists and in four
ophthalmology departments.
Behavioural Optometry and
Behavioural optometry focuses on the role vision plays in learning, human development
and function. Since about 85% of all we learn comes through vision, problems with this
system impact on the learning process, e.g. a child who has difficulty in maintaining focus
at near will likely be someone who avoids sustained close work. Problems with visual
efficiency are often the result of small and subtle visual errors that might be regarded as of
little consequence, but recent research has shown that it is these smaller problems that
are harder to compensate for, and can be the most damaging to development. Some
American studies have shown that almost 25% of children with apparent ‘hyperactivity’
were in fact suffering from poor eye teaming, affecting their ability to stay on task. Other
recent studies have shown that improving visual function can have marked and
measurable effects on learning.
Details of practitioners can be obtained through The British Association of Behavioural
Optometrists which provides postgraduate education in the field, and also maintains a
register of accredited members willing to accept referrals.
Work by Ian Jordan claims that colour can help stabilise the ‘whole system’ in people with
perceptual problems such as dyslexia and dyspraxia. This is explained as due to a slowing
down of information input which allows readers to process the information more easily.
Once vision is stabilised in this way, the perceived movement, blurring or doubling of text
is stopped.
Orthoscopics claims to improve a number of key functions, namely: short-term memory;
speed, fluency and accuracy of reading; handwriting i.e. letter formation and spacing of
words; balance and co-ordination. Colour can also lessen or eliminate headaches if they
are caused by visually stimulation.
It is now accepted that people's reading capability is affected (for many controlled,) by the
colour of the paper or computer screen they are using. Virtually all work in this field is
based on people choosing a colour that they feel comfortable with. Tintavision’s approach
is based on modifying the individual's computer screens. This entails calculating the
setting that gives each person the fastest, most fluent reading experience (tests of rapid
naming and reading fluency are used). The brightness of the target is precisely controlled.
In addition Eyetracking technology is used to steady the eyes of readers and analyse why
people are distracted when reading on white backgrounds but not when using the
calculated optimum colour. Outcomes are checked with a high precision filter system
using a ‘biophysics’ approach. Tintavision claims that the gains from this process are far
greater than those obtained by selecting an overlay or using tinted lenses.
Further tools
The City Coloured Overlay Screener is another approach to tackling visual stress through
the computer. Developed by David Thomson, this program identifies whether colour will be
beneficial and helps to determine the optimum colour, see,uk..
Harris filters ( and Oxford filters (developed by John Stein) are
also available, see
To bring us up to date, two new initiatives have been developed by Chris Singleton’s
team: the Visual Processing Problems Inventory (VPPI) and the computerised ViSS
(VIsual Stress Screener). The latter is currently available for ages 7-11 and 11-17, an
adult version is nearly ready, see
-------------------------------------------------------Finally, in his recent report on Diagnostic Issues in HE, David Grant identified visual stress
in 77% of the 100 dyslexics in his HE sample (the equivalent figure for dyspraxics was
58%). He noted that: while increases in reading speed are usually moderate, there are
‘wow’ occasions when there is a major improvement in reading speed of between 50%
and 75%. One student described the difference between using and not using a tinted
overlay as the words appearing to be either ‘dead or alive’.
I would echo his concluding remarks on visual stress: The question is no longer one of
whether the phenomenon exists. It is a simple question of why isn’t a screening for
visual stress a core element of any diagnostic assessment!
Acknowledgements and thanks are due to Bruce Evans, David Grant, Keith Holland,
Helen Irlen, Peter Irons, Jo O’Neill and Arnold Wilkins for their contributions.
Eden et al (1996) Abnormal processing of visul motion in dyslexia Nature Vol 382
Evans et al (1993) Visual correlates of dyslexia Elsevier Science Pubs.
Evans (2001) Vision and Dyslexia Whurr Publishers
Grant (2006) NADP Technical Briefings: No 1/2006 Neurodiversity: Diagnostic Issues in
Irlen (1991) Reading by the colours Avery.
Jameson (1998) Removing Barriers to Reading National Literacy Trust Journal
Jameson (1995 rev 2000)Visual Processing Checklist (available from the author)
Meares (1980) Figure/ground, brightness, contrast and reading disabilities Visible
Language 14
Wilkins (1995) Visual Stress Oxford University Press
Wilkins (2003) Reading through colour Wiley
Melanie Jameson DYSLEXIA CONSULTANCY MALVERN [email protected]
Published in Patoss Bulletin Nov 2006