Randomised controlled trial of the effect of coloured overlays on the rate of reading of people with specific learning difficulties

Individualized spectral filters alleviate persistent photophobia, headaches and migraines in active duty military and Veterans following brain trauma

PURPOSE

Consistent with association between photophobia and headache, growing evidence suggests an underlying causal relationship between light sensitivity and central pain. We investigated whether an intervention to regulate light sensitivity by filtering only wavelengths causing difficulties for the specific individual could alleviate headaches/migraines resulting from traumatic brain injury (TBI).

METHODS

Secondary data analysis of a clinical database including N = 392 military personnel (97% men, 3% women), ranging in age from 20 to 51 years, diagnosed with TBI, persistent headaches/migraines, and light sensitivity. The average elapsed time from TBI diagnosis to intervention was 3 years. Headache/migraine severity, frequency, medication use, and difficulties related to daily functioning were assessed pre and 4-12 weeks post-intervention with individualized spectral filters.

RESULTS

Monthly migraine frequency decreased significantly from an average of 14.8 to 1.9, with 74% reporting no migraines post-intervention. Prescription and over-the-counter medication use decreased by more than 70%. Individuals also reported significant improvement in light sensitivity, headaches/migraine severity, and physical and perceptual symptoms.

CONCLUSIONS

Wearing individualized spectral filters was associated with symptom relief, increased subjective quality of reported health and well-being, and decreased objective medication use for TBI-related persistent headaches/migraines. These results support a suggested relationship between dysregulated light sensitivity and central regulation of pain.

Room to read: The effect of extra-large letter spacing and coloured overlays on reading speed and accuracy in adolescents with dyslexia

BACKGROUND

Coloured overlay and extra-large letter spacing may improve reading speed and accuracy in individuals with dyslexia; however, research has yet to identify which types of reading errors are diminished.

AIM

To determine the impact of extra-large letter spacing and colour overlay on reading and assess the impact of both interventions on reading errors.

SAMPLE

Thirty-two dyslexic children were matched on age, verbal and non-verbal IQ with 27 children with no diagnosis of dyslexia. The average age of each group was 13 years.

METHOD

Participants read four texts with either standard or extra-large letter spacing with or without a coloured overlay.

RESULTS

Extra-large letter spacing significantly improved reading speed more substantially for the dyslexia group. In addition, extra-large letters significantly reduced the number of missed word errors made by the dyslexia group. In contrast, coloured overlays did not significantly impact reading speed or the reduction of errors.

CONCLUSION

Increasing letter spacing is an effective way for teachers to improve reading skills in students with dyslexia.

Development and feasibility analysis of an assistance system for high school students with dyslexia

BACKGROUND

Students with dyslexia may be at a disadvantage on timed assessments that require reading skills compared to their non-dyslexic peers, even though they are not necessarily less intelligent or less prepared than these students.

AIMS

The study aims to analyze the possible benefits in reading comprehension and reading fluency of students with Dyslexia when using an assistance tool in an evaluation that requires reading skills.

METHODS AND PROCEDURES

Each participant with dyslexia did a reading comprehension assessment in two different reading interfaces: on a white paper and in our previously developed tool, in order to assess and compare their reading comprehension and reading fluency.

OUTCOMES AND RESULTS

The results obtained show that students with dyslexia could benefit from the point of view of fluency and reading comprehension by using compensation software that helps them read in situations of anxiety.

CONCLUSIONS AND IMPLICATIONS

Properly designed assistive tools can enhance the reading skills of young people with dyslexia. The developed tool should be improved considering the improvements proposed in the present studies, in the same way it is suggested to carry out a study with a larger number of participants and evaluate them individually.

Problems in Audiovisual Filtering for Children with Special Educational Needs

There is pervasive evidence that problems in sensory processing occur across a range of developmental disorders, but their aetiology and clinical significance remain unclear. The present study investigated the relation between sensory processing and literacy skills in children with and without a background of special educational needs (SEN). Twenty-six children aged between 7 and 12 years old, from both regular classes and SEN programmes, participated. Following baseline tests of literacy, fine motor skills and naming speed, two sets of instruments were administered: the carer-assessed Child Sensory Profile-2 and a novel Audiovisual Animal Stroop (AVAS) test. The SEN group showed significantly higher ratings on three Child Sensory Profile-2 quadrants, together with body position ratings. The SEN participants also showed a specific deficit when required to ignore an accompanying incongruent auditory stimulus on the AVAS. Interestingly, AVAS performance correlated significantly with literacy scores and with the sensory profile scores. It is proposed that the children with SEN showed a specific deficit in "filtering out" irrelevant auditory input. The results highlight the importance of including analysis of sensory processes within theoretical and applied approaches to developmental differences and suggest promising new approaches to the understanding, assessment, and support of children with SEN.

Spectral Overlays for Reading Difficulties: Oculomotor Function and Reading Efficiency Among Children and Adolescents With Visual Stress

This study analyzed the effects of spectral overlays on ocular motility during reading among a clinical group of children and adolescents experiencing visual–perceptual distortions of text. We reviewed the records of 323 eye-hospital patients diagnosed with visual stress and divided this participant sample into two age-based cohorts: children ( n =  184; Mean [ M] age = 10.1, standard deviation [ SD]  =  1.3 years) and adolescents ( n =  139; M age = 14.6, SD = 1.5 years). We used a Visagraph III Eye-Movement Recording System to record ocular motor efficiency while reading with and without spectral overlays, and we examined the following parameters: (a) Fixations, (b) Regressions, (c) Span of Recognition, (d) Reading Rate, (e) Relative Efficiency, and (f) Comprehension. Our results showed that using one or some combination of 10 participant-selected spectral overlays immediately and significantly ( p <  .001) reduced the number of Fixations and Regressions per 100 words, while there were significant ( p <  .001) gains in positive factors such as Span of Recognition, Reading Rate, Relative Efficiency, and Comprehension. Our findings indicate that spectral filtering can be an effective tool for helping many young patients who experience visual–perceptual distortions while reading. Future expanded research employing eye-tracking technology is clearly needed.

Immediate effects of coloured overlays on the reading performance of preschool children with an autism spectrum disorder using eye tracking

BACKGROUND

Coloured overlays have often been used to improve reading performance in preschool children with an autism spectrum disorder (ASD), however, previous evidence shows conflicts in its application.

AIMS

To investigate the immediate effects of coloured overlays on reading performance using eye tracking in preschool children with ASD and their typical development (TD) counterparts closely matched by chronological age.

METHODS

Forty participants with ASD (n = 20) or TD (n = 20) were recruited by convenience sampling and asked to read aloud numbers randomly arranged on paper. Participants' ocular performance (fixation duration, fixation count, total visit duration), reading speed and number of errors were recorded by eye tracker and digital stopwatch respectively throughout testing with and without coloured overlays.

RESULTS

The findings show that coloured overlays had no significant immediate effect in improving ocular performance and reading speed of children with ASD or TD, although individual improvements were identified in some children with ASD.

CONCLUSIONS

Use of coloured overlays may not be useful to improve reading and ocular performance in children with ASD in one single occasion. The potential effect on reading ability of using coloured overlays repetitively for a longer period needs further investigation.

Irlen syndrome: systematic review and level of evidence analysis

BACKGROUND

Scotopic sensitivity syndrome, later called Meares-Irlen syndrome or simply Irlen syndrome (IS) has been described as symptoms of poor reading ability due to poor color matching and distorted graphic images. Individuals with this syndrome are considered slow, ineffective readers with low comprehension and visual fatigue. It is still uncertain whether the disease pathophysiology is an independent entity or part of the dyslexia spectrum. Nevertheless, treatments with lenses and colored filters have been proposed to alleviate the effect of the luminous contrast and improve patients' reading performance. However, no evidence of treatment effectiveness has been achieved.

OBJECTIVE

The aim of the present study was to obtain evidence about IS etiology, diagnosis and intervention efficacy.

METHODS

A systematic review was performed covering the available studies on IS, assessing the available data according to their level of evidence, focusing on diagnostic tools, proposed interventions and related outcomes.

RESULTS

The data showed high heterogeneity among studies, and lack of evidence on the existence of IS and treatment effectiveness.

CONCLUSION

The syndrome as described, as well as its treatments, require further strong evidence.

Effects of Spectral Overlays on Reading Performance of Brazilian Elementary School Children

OBJECTIVE

To investigate the effects of spectral overlays on reading performance of Brazilian elementary school children.

METHODS

Sixty-eight children (aged 9-12 years) enrolled in the 5th and 6th grade were included in the study. The Rate of Reading Test (RRT - Brazilian Portuguese version) was used to evaluate reading speed and the Irlen Reading Perceptual Scale was used to allocate the sample according to reading difficulty/discomfort symptoms and to define the optimal spectral overlays.

RESULTS

A total of 13% of the children presented an improvement of at least 15% in reading speed with the use of spectral overlays. Pupils with severe reading difficulties tended to have more improvement in RRT with spectral overlays. Children with severe reading discomfort obtained the highest gains in RRT, with an average of 9.6% improvement with intervention, compared to a decrease of -8.2% in the control group. Participants with severe discomfort had an odds ratio of 3.36 to improve reading speed with intervention compared to the control group.

CONCLUSION

The use of spectral overlays can improve reading performance, particularly in those children with severe visual discomfort.

What is Developmental Dyslexia?

Until the 1950s, developmental dyslexia was defined as a hereditary visual disability, selectively affecting reading without compromising oral or non-verbal reasoning skills. This changed radically after the development of the phonological theory of dyslexia; this not only ruled out any role for visual processing in its aetiology, but it also cast doubt on the use of discrepancy between reading and reasoning skills as a criterion for diagnosing it. Here I argue that this theory is set at too high a cognitive level to be explanatory; we need to understand the pathophysiological visual and auditory mechanisms that cause children's phonological problems. I discuss how the 'magnocellular theory' attempts to do this in terms of slowed and error prone temporal processing which leads to dyslexics' defective visual and auditory sequencing when attempting to read. I attempt to deal with the criticisms of this theory and show how it leads to a number of successful ways of helping dyslexic children to overcome their reading difficulties.

Coloured overlays and precision-tinted lenses: poor repeatability in a sample of adults and children diagnosed with visual stress

PURPOSE

Visual stress consists of perceived distortions or discomfort while reading. It is claimed that these symptoms are alleviated by viewing through coloured lenses or overlays, with a specific colour required for each individual. This has been explained on the basis of altered visual cortex excitation as affected by the spectral content of the viewing light. If symptoms are indeed alleviated by a particular colour that has an impact on the individual's visual system, we would expect that selection of the most beneficial colour would be repeatable. The aim of this study was to determine whether this is the case.

METHODS

Twenty-one participants (mean age 26 years (range 8-55 years); 12 female, nine male) with visual stress and no other uncorrected ocular or visual anomaly were recruited. Each participant selected the colour most beneficial in alleviating their symptoms from a standard set of 10 coloured overlays, and underwent intuitive colorimetry in which the most beneficial of a wide range of chromatic illuminance settings was selected. Without prescribing an overlay at the first appointment, this process was repeated on a second occasion at a mean of 25 days later.

RESULTS

About half of the participants (n = 10) chose the same (n = 7) or similar (with one common colour in both choices; n = 3) coloured overlay on the two occasions, while 11 participants chose a completely different overlay colour. Across all participants, the colorimetry setting shifted by, on average, 9.6 just noticeable differences, indicating that the colours were perceptually very different.

CONCLUSION

These findings suggest that people with visual stress are unlikely to find exactly the same colour to be optimal on different occasions, and raise questions about the need for precise colour specification in tinted lenses for visual stress.

The effect of coloured overlays and lenses on reading: a systematic review of the literature

PURPOSE

There are many anecdotal claims and research reports that coloured lenses and overlays improve reading performance. Here we present the results of a systematic review of this literature and examine the quality of the evidence.

METHODS

We systematically reviewed the literature concerning the effect of coloured lenses or overlays on reading performance by searching the PsychInfo, Medline and Embase databases. This revealed 51 published items (containing 54 data sets). Given that different systems are in use for issuing coloured overlays or lenses, we reviewed the evidence under four separate system headings (Intuitive, Irlen, Harris/Chromagen and Other), classifying each published item using the Cochrane Risk of Bias tool.

RESULTS

Although the different colour systems have been subjected to different amounts of scientific scrutiny, the results do not differ according to the system type, or whether the sample under investigation was classified as having visual stress (or a similarly defined condition), reading difficulty, or both. The majority of studies are subject to 'high' or 'uncertain' risk of bias in one or more key aspects of study design or outcome, with studies at lower risk from bias providing less support for the benefit of coloured lenses/overlays on reading ability. While many studies report improvements with coloured lenses, the effect size is generally small and/or similar to the improvement found with a placebo condition. We discuss the strengths and shortcomings of the published literature and, whilst acknowledging the difficulties associated with conducting trials of this type, offer some suggestions about how future trials might be conducted.

CONCLUSIONS

Consistent with previous reviews and advice from several professional bodies, we conclude that the use of coloured lenses or overlays to ameliorate reading difficulties cannot be endorsed and that any benefits reported by individuals in clinical settings are likely to be the result of placebo, practice or Hawthorne effects.

A systematic review of controlled trials on visual stress using Intuitive Overlays or the Intuitive Colorimeter

Claims that coloured filters aid reading date back 200 years and remain controversial. Some claims, for example, that more than 10% of the general population and 50% of people with dyslexia would benefit from coloured filters lack sound evidence and face validity. Publications with such claims typically cite research using methods that have not been described in the scientific literature and lack a sound aetiological framework. Notwithstanding these criticisms, some researchers have used more rigorous selection criteria and methods of prescribing coloured filters that were developed at a UK Medical Research Council unit and which have been fully described in the scientific literature. We review this research and disconfirm many of the more extreme claims surrounding this topic. This literature indicates that a minority subset of dyslexics (circa 20%) may have a condition described as visual stress which most likely results from a hyperexcitability of the visual cortex. Visual stress is characterised by symptoms of visual perceptual distortions, headaches, and eyestrain when viewing repetitive patterns, including lines of text. This review indicates that visual stress is distinct from, although sometimes co-occurs with, dyslexia. Individually prescribed coloured filters have been shown to improve reading performance in people with visual stress, but are unlikely to influence the phonological and memory deficits associated with dyslexia and therefore are not a treatment for dyslexia. This review concludes that larger and rigorous randomised controlled trials of interventions for visual stress are required. Improvements in the diagnosis of the condition are also a priority.

Does Gender Influence Colour Choice in the Treatment of Visual Stress?

Purpose

Visual Stress (VS) is a condition in which words appear blurred, in motion, or otherwise distorted when reading. Some people diagnosed with VS find that viewing black text on white paper through coloured overlays or precision tinted lenses (PTLs) reduces symptoms attributed to VS. The aim of the present study is to determine whether the choice of colour of overlays or PTLs is influenced by a patient’s gender.

Methods

Records of all patients attending a VS assessment in two optometry practices between 2009 and 2014 were reviewed retrospectively. Patients who reported a significant and consistent reduction in symptoms with either overlay and or PTL were included in the analysis. Overlays and PTLs were categorized as stereotypical male, female or neutral colours based on gender preferences as described in the literature. Chi-square analysis was carried out to determine whether gender (across all ages or within age groups) was associated with overlay or PTL colour choice.

Results

279 patients (133 males and 146 females, mean age 17 years) consistently showed a reduction in symptoms with an overlay and were included. Chi-square analysis revealed no significant association between the colour of overlay chosen and male or female gender (Chi-square 0.788, p = 0.674). 244 patients (120 males and 124 females, mean age 24.5 years) consistently showed a reduction in symptoms with PTLs and were included. Chi-square analysis revealed a significant association between stereotypical male/female/neutral colours of PTLs chosen and male/female gender (Chi-square 6.46, p = 0.040). More males preferred stereotypical male colour PTLs including blue and green while more females preferred stereotypical female colour PTLs including pink and purple.

Conclusions

For some VS patients, the choice of PTL colour is influenced not only by the alleviation of symptoms but also by other non-visual factors such as gender.

Attentional Gating in Primary Visual Cortex: A Physiological Basis for Dyslexia

The visual magnocellular pathway is known to play a central part in visuospatial attention and in directing attention to specific parts of the visual world in serial search. It is proposed that, in the case of reading, this mechanism is trained to perform a sequential gating of visual information coming into the primary visual cortex to enable further orderly processing by the ventral stream. This scheme, taken together with the potential for plasticity between the different afferent channels in the case of a relative impairment of the magnocellular system, can provide some limited rationale for the beneficial effects that have been claimed for the use of coloured overlays and glasses.

Evaluation of visual stress symptoms in age-matched dyslexic, Meares-Irlen syndrome and normal adults

AIM

To examine the prevalence of dyslexia and Meares-Irlen syndrome (MIS) among female students and determine their level of visual stress in comparison with normal subjects.

METHODS

A random sample of 450 female medical students of King Saud University Riyadh (age range, 18-30y) responded to a wide range of questions designed to accomplish the aims of this study. The detailed questionnaire consisted of 54 questions with 12 questions enquiring on ocular history and demography of participants while 42 questions were on visual symptoms. Items were categorized into critical and non-critical questions (CQ and NCQ) and were rated on four point Likert scale. Based on the responses obtained, the subjects were grouped into normal (control), dyslexic with or without MIS (Group 1) and subjects with MIS only (Group 2). Responses were analysed as averages and mean scores were calculated and compared between groups using one way analysis of variance to evaluate total visual stress score (TVSS=NCQ+CQ), critical and non-critical visual stress scores. The relationship between categorical variables such as age, handedness and condition were assessed with Chi-square test.

RESULTS

The completion rate was 97.6% and majority of the respondents (92%) were normal readers, 2% dyslexic and 6% had MIS. They were age-matched. More than half of the participants had visited an eye care practitioner in the last 2y. About 13% were recommended eye exercises and one participant experienced pattern glare. Hand preference was not associated with any condition but Group 1 subjects (3/9, 33%) were significantly more likely to be diagnosed of lazy eye than Group 2 (2/27, 7%) and control (27/414, 7%) subjects. The mean±SD of TVSS responses were 63±14 and it was 44±9 for CQ and 19±5 for NCQ. Responses from all three variables were normally distributed but the CQ responses were on the average more positive (82%) in Group 2 and less positive (46%) in Group 1 than control. With NCQ, the responses were equally less positive in Group 1 and 2 than control. Group 2 subjects showed significantly higher TVSS (P=0.002), NCQ (P=0.006) and CQ (P=0.008) visual stress scores than control but no difference between Group 1 and control subjects, was observed for all scores (P>0.05, for all comparisons).

CONCLUSION

The prevalence of dyslexia and MIS among Saudi female students was 2% and 6%, respectively. Critical questions performed best for assessing visual stress symptoms in dyslexic and MIS subjects. Generally, students with MIS were more sensitive to visual stress than normal students but dyslexics were more likely to present with a lazy eye than MIS and normal readers.

The Interpretation of Emotion from Facial Expression for Children with Visual Processing Problems

A significant proportion of people with learning difficulties have social problems, which are often considered to be the product of school failure. However, a number of studies have suggested that these social skill problems may relate to the inability to decode subtle visual cues of body language and facial expression. The majority of studies of facial expression, however, have viewed learning disability as a unitary condition, without taking account of specific sub‐types which may have more difficulty in processing visual cues, especially for facial emotion. This study investigated children aged 8 to 12 years who were divided into three learning disability sub‐groups: 1) a visual‐perceptual sub‐type called Irlen Syndrome (n=41); 2) a group with learning disabilities, but no indications of Irlen Syndrome (n=30); and 3) a normally achieving control group (n=31). The Irlen Syndrome sub‐group had significantly lower scores for interpreting emotion from facial expression than the two other groups. The learning disabled non‐lrlen sub‐group also had significantly lower scores than the control group, but with much smaller levels of significance than those between the Irlen and control groups.

Using coloured filters to reduce the symptoms of visual stress in children with reading delay

The way citation distortion can create unfounded authority in a subject area is exemplified in the paper "Coloured filters to reduce the symptoms of visual stress in children with reading delay", published early online in the Scandinavian Journal of Occupational Therapy. The diagnostic criteria for visual stress remain unclear, for which reason the prevalence figures should be viewed with scepticism. Randomized controlled trials with placebo control groups consistently show improvements in experimental and control lenses. This letter is a critical review of the evidence cited in the introduction to the paper. In the light of this the most likely explanation for their results is the placebo effect.

Identifying visual stress during a routine eye examination

PURPOSE

To investigate whether the clinical tests used in routine eye examinations can identify adults whose reading rate increases with their preferred coloured overlay(s).

METHODS

Routine optometric tests were used to measure 73 undergraduate students' refractive error, visual acuity, stereo-acuity, amplitude of accommodation, near point of convergence, associated heterophoria at near, colour vision and ocular motility. Participants chose an overlay or combination of overlays with colour optimal for clarity, and completed the Wilkins Rate of Reading Test with and without an overlay(s) of this colour.

RESULTS

Overall, there was a significant increase in reading speed with overlay (t(72)=-5.26, p<0.0005). Twenty-six participants (36%) increased their reading rate by >5% with their chosen coloured overlay(s). Ten participants (14%) had a reading speed increase of >10%. The increase in reading speed was not significantly associated with any clinical finding.

CONCLUSION

Tests which are completed in routine eye examinations did not identify those participants who benefitted from coloured overlays in terms of reading speed.

A comparison of two-coloured filter systems for treating visual reading difficulties

Purpose

Visual disturbances that make it difficult to read text are often termed “visual stress”. Coloured filters in spectacles may help some children overcome reading problems that are often caused by visual stress. It has been suggested that for optimal effect each child requires an individually prescribed colour for each eye, as determined in systems such as the “Harris Foundation” coloured filters. Alternatively, it has been argued that only blue or yellow filters, as used in the “Dyslexia Research Trust” (DRT) filter system, are necessary to affect the underlying physiology.

Method

A randomised, double blind trial with 73 delayed readers, was undertaken to compare changes in reading and spelling as well as irregular and non-word reading skills after 3 months of wearing either the Harris or the DRT filters.

Results

Reading improved significantly after wearing either type of filter (t = −8.4, p < 0.01), with 40% of the children improving their reading age by 6 months or more during the 3 month trial. However, spelling ability (t = 2.1, p = 0.05) and non-word reading (f = 4.7, p < 0.05) improved significantly more with the DRT than with the Harris filters.

Conclusion

Education and rehabilitation professionals should therefore, consider coloured filters as an effective intervention for delayed readers experiencing visual stress.

Effects of wearing yellow spectacles on visual skills, reading speed, and visual symptoms in children with reading difficulties

BACKGROUND

Possible beneficial effects of yellow-tinted spectacle lenses on binocular vision, accommodation, oculomotor scanning, reading speed and visual symptoms were assessed in children with reading difficulties.

METHODS

A longitudinal prospective study was performed in 82 non-dyslexic children with reading difficulties in grades 3-6 (aged 9-11 years) from 11 elementary schools in Madrid (Spain). The children were randomly assigned to two groups: a treatment (n = 46) and a without-treatment group (n = 36). Children in the treatment group wore yellow spectacle lenses with best correction if necessary over 3 months (in school and at home). The tests were first undertaken without the yellow filter. With best spectacle correction in each subject, measurements were made of: distance and near horizontal heterophoria, distance and near horizontal fusional vergence ranges, the accommodative convergence/accommodation (AC/A) ratio, near point of convergence (NPC), stereoacuity, negative relative accommodation (NRA) and positive relative accommodation (PRA), monocular accommodative amplitude (MAA), binocular accommodative facility (BAF), oculomotor scanning, and reading speed (words per minute). The Convergence Insufficiency Symptom Survey (CISS) questionnaire was completed by all children. After the 3-month period, measurements were repeated with the yellow lenses (treatment group) or without the yellow lenses (without-treatment group) but with refractive correction if needed.

RESULTS

Over the 3 months, the two groups showed similar mean changes in the variables used to assess binocular vision, accommodation, oculomotor scanning, and reading speed. However, mean relative changes in convergence insufficiency symptoms differed significantly between the groups (p = 0.01).

CONCLUSION

No effects of wearing yellow spectacles emerged on binocular vision, accommodation, oculomotor scanning, and reading speed in children with reading difficulties. The yellow filter had no effect even in children with low MAA and BAF. The reduction in visual symptoms observed in children with reading difficulties using the yellow filters was clinically insignificant.

A Prospective Genetic Marker of the Visual-Perception Disorder Meares-Irlen Syndrome

Prior investigations of scotopic sensitivity or Meares-Irlen syndrome have identified several features also found in attention deficit/hyperactivity disorder, chronic fatigue syndrome, and a subtype of dyslexia in which visual recognition is the primary deficit. In particular, anomalies in lipid metabolism, including low essential fatty acid status and decreased serum cholesterol, have been identified in all three disorders. Genetic expression of the transporter molecule apolipoprotein B-100 (APOB) has been correlated with abnormal lipid metabolism, particularly in relation to levels of cholesterol. Cholesterol esters are important carriers of essential fatty acids entering the retina. The APOB gene coding for apolipoprotein B-100 is located on the short arm of Chromosome 2, and closely neighbours a gene (DYX3) known to confer susceptibility to dyslexia. The APOB locus is also recognised as being one of the most highly polymorphic regions of the human genome, and thus provides a promising tool for genetic researchers. In this pilot study, certain allelic variants of the APOB gene were more common in participants diagnosed with Meares–Irlen syndrome than in individuals without the condition. This study appears to be a first in which a condition known to cause reading difficulties has been associated with the APOB gene.

Irlen colored overlays do not alleviate reading difficulties

OBJECTIVES

To test the efficacy of Irlen colored overlays for alleviating reading difficulties ostensibly caused by Irlen syndrome, a proposed perceptual disorder with controversial diagnostic status.

PARTICIPANTS AND METHODS

Sixty-one schoolchildren (aged 7-12 years) with reading difficulties were assessed by an Irlen diagnostician. We used a within-subject study design to examine differences in reading rate across 3 conditions: using an overlay of a prescribed color; using an overlay of a nonprescribed color; and using no overlay. In a subset of 44 children, all of whom had a diagnosis of Irlen syndrome, we also used a between-group design to test the effects of Irlen colored overlays on a global reading measure.

RESULTS

The Irlen diagnostician diagnosed Irlen syndrome in 77% of our poor readers. We found no evidence for any immediate benefit of Irlen colored overlays as measured by the reading-rate test or the global reading measure.

CONCLUSIONS

Our data suggest that Irlen colored overlays do not have any demonstrable immediate effect on reading in children with reading difficulties.

An evaluation of clinical treatment of convergence insufficiency for children with reading difficulties

Background

The present study investigates two different treatment options for convergence insufficiency CI for a group of children with reading difficulties referred by educational institutes to a specialist eye clinic in Vienna.

Methods

One hundred and thirty four subjects (aged 7-14 years) with reading difficulties were referred from an educational institute in Vienna, Austria for visual assessment. Each child was given either 8Δ base-in reading spectacles (n = 51) or computerised home vision therapy (HTS) (n = 51). Thirty two participants refused all treatment offered (clinical control group). A full visual assessment including reading speed and accuracy were conducted pre- and post-treatment.

Results

Factorial analyses demonstrated statistically significant changes between results obtained for visits 1 and 2 for total reading time, reading error score, amplitude of accommodation and binocular accommodative facility (within subjects effects) (p < 0.05). Significant differences were also demonstrated between treatment groups for total reading time, reading error score and binocular accommodative facility (between subjects effects) (p < 0.05).

Conclusions

Reading difficulties with no apparent intellectual or psychological foundation may be due to a binocular vision anomaly such as convergence insufficiency. Both the HTS and prismatic correction are highly effective treatment options for convergence insufficiency. Prismatic correction can be considered an effective alternative to HTS.

The Role of Attributional Bias and Visual Stress on the Improvement of Reading Speed Using Colored Filters

This study tested the predictions derived from two explanatory theoretical models of the effects of colored filters on reading speed: the theory of attributional bias and the theory of visual stress associated with reading. The experimental group consisted of 27 secondary school students (14 boys, 13 girls) diagnosed with the Meares-Irlen syndrome; the control group had 27 students paired in age and sex with the experimental group. The mean age of the sample was 12 years, 10 months ( SD = 8.9 mo.). The effects of colored filters on reading speed and accuracy were tested using a word reading test and a visual stress induction text. The presentation method tapped individuals' visual sensitivity and response criteria. The results support some predictions of the theory of attributional bias, but more research is needed to assess each theory of reading speed.

Learning disabilities, dyslexia, and vision

Learning disabilities constitute a diverse group of disorders in which children who generally possess at least average intelligence have problems processing information or generating output. Their etiologies are multifactorial and reflect genetic influences and dysfunction of brain systems. Reading disability, or dyslexia, is the most common learning disability. It is a receptive language-based learning disability that is characterized by difficulties with decoding, fluent word recognition, rapid automatic naming, and/or reading-comprehension skills. These difficulties typically result from a deficit in the phonologic component of language that makes it difficult to use the alphabetic code to decode the written word. Early recognition and referral to qualified professionals for evidence-based evaluations and treatments are necessary to achieve the best possible outcome. Because dyslexia is a language-based disorder, treatment should be directed at this etiology. Remedial programs should include specific instruction in decoding, fluency training, vocabulary, and comprehension. Most programs include daily intensive individualized instruction that explicitly teaches phonemic awareness and the application of phonics. Vision problems can interfere with the process of reading, but children with dyslexia or related learning disabilities have the same visual function and ocular health as children without such conditions. Currently, there is inadequate scientific evidence to support the view that subtle eye or visual problems cause or increase the severity of learning disabilities. Because they are difficult for the public to understand and for educators to treat, learning disabilities have spawned a wide variety of scientifically unsupported vision-based diagnostic and treatment procedures. Scientific evidence does not support the claims that visual training, muscle exercises, ocular pursuit-and-tracking exercises, behavioral/perceptual vision therapy, "training" glasses, prisms, and colored lenses and filters are effective direct or indirect treatments for learning disabilities. There is no valid evidence that children who participate in vision therapy are more responsive to educational instruction than children who do not participate.

A placebo-controlled trial of tinted lenses in adolescents with good and poor academic performance: reading accuracy and speed

Purpose

A placebo-controlled, double-masked study was designed in order to evaluate the effect of tinted lenses in adolescents with good and poor academic performance.

Methods

Teenagers from two different age groups were enrolled in this study, after ascertaining that no uncorrected visual anomalies were present. A rate of reading test was developed for Catalan as a first language and students were asked to read it aloud, in two different sessions. Students first read the test without lenses and, later, they read it again without lenses, with their lenses of choice and with a placebo set of clear lenses. Reading speed and accuracy were monitored.

Results

No significant difference was encountered between the baseline reading speed and accuracy from the first and second sessions, thus ruling out any effect due to experience or training. When comparing reading speed and accuracy without lenses, in placebo conditions, and with tinted lenses, reading accuracy was discovered to be more sensitive than reading speed in order to differentiate between these conditions. These differences were more noticeable when the group with poor academic performance was evaluated, in contrast to the group with good academic performance or the whole group.

Conclusion

It was concluded that reading accuracy should be evaluated as well as reading speed and that lenses were more beneficial if only adolescents with poor academic performance were targeted.

Dyslexia: a review of two theories

Optometrists will frequently see patients, who may have a diagnosis or a suspected diagnosis of dyslexia (specific reading disorder) and will need to manage and counsel such patients. There are many propounded theories on the cause(s) of dyslexia. Although most professionals in this area consider that dyslexia is chiefly a linguistic disorder, the possibility of a visual component is contentious. This article is a selective review of two commonly discussed theories that suggest a visual component in dyslexia; the magnocellular deficit theory and Meares-Irlen syndrome.

Coloured filters and reading accuracy, comprehension and rate: a placebo-controlled study

Literature suggests that visuoperceptual deficits not normally assessed by eye examinations may be responsible for certain reading disabilities. Previous studies indicate that the use of nonoptical coloured filters may reduce these deficits and improve reading performance. Present research involved 49 participants with visuo-perceptual reading disabilities. Participants were divided into a control group who received no intervention, a placebo group who received filters in a colour complementary to the individual's optimal colour, and an experimental group who received specifically matched coloured filters. At posttest the experimental group reported statistically significantly fewer visual discomfort symptoms. The remainder of the results were, however, inconsistent. Some potential explanations are explored.

Visual processing characteristics of children with Meares-Irlen syndrome

The potential role of visual processing deficits in reading difficulty was brought to public attention by claims that a large proportion of children with dyslexia suffer from a perceptual dysfunction currently referred to as Meares-Irlen syndrome (MISViS). A previous study showing that visual perceptual measures involving visual memory and discrimination predict independent variance in reading achievement [J. Learn. Disabil. 28 (1995) 216] provides a basis to examine their relationships with the diagnostic criteria of MISViS. This study examined these visual processing characteristics in 36 eight- to ten-year-old children, half of whom were experiencing reading difficulty. Children were assessed for MISViS by Irlen screeners; approximately half of the participants in each group were positively identified. Concurrent performance on standardized visual processing tests showed that while a positive diagnosis of MISViS is not indicative of reading ability, nor in particular of a visual-processing deficit subtype identified by Watson and Willows [J. Learn. Disabil. 28 (1995) 216], MISViS can indicate visual processing difficulties potentially related to visual attention inefficiency.

Personality dimensions of people who suffer from visual stress

Personality dimensions of participants who suffer from visual stress were compared with those of normal participants using the Eysenck Personality Inventory. Extraversion-Introversion scores showed no significant differences between the participants who suffered visual stress and those who were classified as normal. By contrast, significant differences were found between the normal participants and those with visual stress in respect of Neuroticism-Stability. These differences accord with Eysenck's personality theory which states that those who score highly on the neuroticism scale do so because they have a neurological system with a low threshold such that their neurological system is easily activated by external stimuli. The findings also relate directly to the theory of visual stress proposed by Wilkins which postulates that visual stress results from an excess of neural activity. The data may indicate that the excess activity is likely to be localised at particular neurological regions or neural processes.

ERGs and psychophysical thresholds in students with reading discomfort

PURPOSE

Symptoms of reading discomfort include unpleasant somatic and perceptual effects, such as eye-strain, headache, and blurred text, despite normal visual acuity. Reading discomfort has been proposed to be the result of increased noise in the visual system. Several studies have suggested that the symptoms can be minimized by having the subject wear colored filters. Thus, there may be abnormal neural processing in the cone pathways. This study measured L- and M-cone isolating (1) ERGs and (2) psychophysical thresholds in normal and reading discomfort subjects to determine if cone processing was abnormal in the reading discomfort population.

METHODS

Twenty-two normal and nineteen reading discomfort college students took part in this study. The normal subjects had Conlon survey scores within 0.5 SD of the mean and the reading discomfort subjects had scores >1.5 SD above the mean. ERGs were determined for a range (5 to 15%) of L- and M-cone contrasts. Slopes were determined for the L- and M-cone ERG amplitudes for each subject. Psychophysical thresholds were determined with a 2AFC technique combined with a 3-up and 1-down staircase procedure that terminated after 18 reversals occurred. The threshold was calculated as the average of the last 8 reversals.

RESULTS

The average ERG slopes were not significantly different between the normal and reading discomfort groups (L-Cone, p = 0.086; M-Cone, p = 0.47). The L/M cone ratios for the slopes were not significantly different (p = 0.55). The log of the color contrast thresholds were not significantly different between the normal and reading discomfort groups (L-Cone, p = 0.97; M-Cone, p = 0.92).

CONCLUSIONS

L- and M- cone ERG contrast gains and psychophysical estimates of color contrast thresholds were not significantly different. These results do not support the noisy visual system hypothesis of reading discomfort.

[A critical view of alternative methods for treating visual complaints]

Irlen therapy, visual training, training of ocular motor control, and the correction method of H.-J. Haase represent a diversity of treatment methods that are mainly aimed at dyslexia, fatigue while reading, and general lack of concentration. We summarize the theoretical background of these methods, treatment approaches, and related clinical trials. None of these methods, because of incorrect theoretical concepts and an attempt to simplify the underlying causes, was found to have a specific influence on the patients' complaints. The absence of specific therapeutic effects and the high costs and time expenditure required should discourage practitioners from recommending these methods.

Computerized screening for visual stress in children with dyslexia

Visual stress-a condition in which unpleasant visual symptoms are experienced when reading-has been reported to be more prevalent in dyslexic individuals but at the present time the relationship between dyslexia and visual stress remains controversial. ViSS, a computerized visual stress screener that incorporates reading-like visual search, has recently shown promise in studies with unselected samples of primary and secondary school children. This study investigated the use of ViSS with dyslexic children. Dyslexic children identified as having high visual stress showed significantly higher per cent increases in reading rate with a coloured overlay and reported significantly higher critical symptoms of visual stress, compared to dyslexic children with low visual stress. The same results were found for reading-age controls, indicating that ViSS can be equally effective with normal readers as well as with children with dyslexia. Compared to reading-age controls, dyslexic children were found to have significantly higher susceptibility to visual stress, significantly larger per cent increases in reading rate with an overlay, and significantly higher critical and non-critical symptoms of visual stress. Extrapolated to unselected population samples, the data also suggest that visual stress is more likely to be found in people with dyslexia than in people who do not have dyslexia. These results, which point to an important link between the two conditions, are discussed in relation to current theories that attribute visual stress to either a magnocellular dysfunction or cortical hyperexcitability.

The effect of coloured overlays on reading ability in children with autism

Abnormalities of colour perception in children with autistic spectrum disorders have been widely reported anecdotally. However, there is little empirical data linking difficulties in colour perception with academic achievement. The Wilkins Rate of Reading Test was administered with and without Intuitive Coloured Overlays to 19 children with autistic spectrum disorders and to the same number of controls individually matched for age and intelligence. Findings showed that 15 out of 19 (79%) children with autism showed an improvement of at least 5% in reading speed when using a coloured overlay. In contrast only 3 of 19 (16%) control group children showed such an improvement. The findings suggest that coloured overlays may provide a useful support for reading for children with autism.

Screening for Meares?Irlen sensitivity in adults: can assessment methods predict changes in reading speed?

Two methods of assessing candidates for coloured overlays were compared with the aim of determining which method had the most practical utility. A total of 58 adults were assessed as potential candidates for coloured overlays, using two methods; a questionnaire, which identified self-reported previous symptoms, and a measure of perceptual distortions immediately prior to testing. Participants were classified as normal, Meares-Irlen sensitive, and borderline sensitive. Reading speed was measured with and without coloured overlays, using the Wilkins Rate of Reading Test and the change in speed was calculated. Participants classified as normal did not show any significant benefit from reading with an overlay. In contrast, a significant reading advantage was found for the borderline and Meares-Irlen participants. Current symptom rating was found to be a significant predictor of the change in reading speed, however the previous symptom rating was not found to be a reliable predictor. These data indicate that the assessment of perceptual distortions immediately prior to measuring colour preference and reading speed is the most meaningful method of assessing pattern glare and determining the utility of coloured overlays.

The effects of coloured light filter overlays on reading rates in age-related macular degeneration

PURPOSE

To determine the effect of coloured light filter overlays on reading rates for people with age-related macular degeneration (AMD).

METHOD

Using a prospective clinical trial design, we examined the null hypothesis that coloured light filter overlays do not improve reading rates in AMD when compared to a clear filter. Reading rates for 12 subjects with non-exudative AMD, associated with a relative scotoma and central fixation (mean age 81 years, SD 5.07 years) were determined using the Rate of Reading Test (printed, nonsense, lower case sans serif, stationary text) with 10 different, coloured light filter overlays (Intuitive Overlays); figures in brackets are percentage transmission values); rose (78%), pink (78%), purple (67%), aqua (81%), blue (74%), lime-green (86%), mint-green (85%), yellow (93%), orange (83%) and grey (71%). A clear overlay (Roscolene # 00) (360 cdm-2) with 100% transmittance was used as a control.

RESULTS

Anova indicated that there was no statistically significant difference in reading rates with the coloured light filter overlays compared to the clear filter. Furthermore, chi-squared analysis indicated that the rose, purple and blue filters had a significantly poorer overall ranking in terms of reading rates compared to the other coloured and clear light filters.

CONCLUSION

Coloured light filter overlays are unlikely to provide a clinically significant improvement in reading rates for people with non-exudative AMD associated with a relative scotoma and central fixation.

Developmental dyslexia: specific phonological deficit or general sensorimotor dysfunction?

Dyslexia research now faces an intriguing paradox. It is becoming increasingly clear that a significant proportion of dyslexics present sensory and/or motor deficits; however, as this 'sensorimotor syndrome' is studied in greater detail, it is also becoming increasingly clear that sensory and motor deficits will ultimately play only a limited role in a causal explanation of specific reading disability.

The effect of coloured filters on the rate of reading in an adult student population

Meares-Irlen Syndrome is characterised by visual stress (visual discomfort) and visual perceptual distortions that can be alleviated by individually prescribed coloured filters. The benefit from coloured filters can be demonstrated with the Wilkins Rate of Reading Test (WRRT). Previous research using individually prescribed coloured overlays (sheets of plastic placed on a page) found that between one-fifth and one-third of unselected school-children show a significant (> 5%) improvement in their rate of reading with their chosen overlay. This 5% cut-off has good sensitivity and specificity for predicting those children who will continue to voluntarily use their overlay for a sustained period. Previous research has concentrated on children, and we sought to investigate the immediate effect of overlays on rate of reading in an adult population. Subjects were 113 unselected university students who answered a symptom questionnaire and were tested with the Wilkins Intuitive Overlays and WRRT. Some symptoms were common: 73% reported sore or tired eyes when reading and 40% reported four to 12 headaches a year. One hundred of the subjects chose an overlay as improving their immediate perception of text. These subjects were significantly more likely to report perceptual distortions and visual discomfort on viewing text than subjects who did not choose an overlay. The 100 subjects read 3.8% faster with the overlay than without any overlay (p < 0.00001), whereas the 13 subjects who did not choose an overlay read 1.7% slower with a placebo overlay than without (p = 0.37). Of the subjects who chose an overlay, 38% read more than 5% faster with the overlay and 2% read more than 25% faster. These results are comparable with those obtained for children. We conclude that Meares-Irlen Syndrome is likely to be as common in adults as it is in children.

Coloured overlays and their effects on reading speed: a review

Coloured overlays can reduce symptoms of visual stress and improve reading speed. These benefits are reliable and are not attributable simply to placebo effects. Five percent of children in mainstream education read at least 25% more quickly with an overlay, provided they have chosen the colour. The suboptimal design of children's text and the high level of classroom lighting may be partly responsible.