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

Hebbian Control of Fixations in a Dyslexic Reader: A Case Report

When reading, dyslexic readers exhibit more and longer fixations than normal readers. However, there is no significant difference when dyslexic and control readers perform only visual tasks on a string of letters, showing the importance of cognitive processes in reading. This linguistic and cognitive processing requirement in reading is often perturbed for dyslexic readers by perceived additional letters and word mirror images superposed on the primary images on the primary cortex, inducing internal visual crowding. Here, we show that while for a normal reader, the number and the duration of fixations remain invariant whatever the nature of the lighting, the excess of fixations and total duration of reading can be controlled for a dyslexic reader using the Hebbian mechanisms to erase extra images in optimized pulse-width lighting. In this case, the number of fixations can then be reduced by a factor of about 1.8, recovering the normal reading experiment.

An Exploratory Assessment of Self-Reported Satisfaction with Infrastructure and Out-of-Home Activities for People with Vision Impairments

PURPOSE

The purpose of this study is to assess the satisfaction levels of people with VI with regard to infrastructure and outdoor activities. Furthermore, this study aims to develop an assessment model for the levels of difficulty in using public transport.

METHODS

Participants in a standardized survey questionnaire included 74 participants with VI. Three assessment-ordered probit models were estimated based on self-reported responses.

RESULTS

Estimation results revealed that the use of public transport is extremely difficult for 83.47% of older participants. In addition, 84.2% of people with albinism have extreme difficulty using public transport. Furthermore, 53.98% of people with restricted horizontal and vertical fields face extreme difficulty using public transport. There was dissatisfaction with outdoor activities among 97.40% of people with macular disease. The results show that 51.70% of people with normal or near-normal horizontal visual fields and restricted vertical planes are satisfied with their level of outdoor activity while 72.65% of people with retinal diseases expressed dissatisfaction with the existing infrastructure.

CONCLUSION

This study revealed that the experiences of people with VI are heterogeneous and depend on their eye condition, access to assistive technology, and socioeconomic characteristics. Results clearly show evidence of heterogeneity among individuals with VI. The combination of horizontal and vertical restrictions yields random parameters, underscoring the heterogeneous experiences of people with VI, influenced by their eye condition and access to assistive devices. Our results have important implications for developing targeted interventions to enhance the mobility of people with VI.

The Use of Chromagen Lenses in Different Ocular and Non-ocular Conditions: A Prospective Cohort Study

Background

In this study, we aimed to evaluate the efficacy of chromagen lenses and compare the pre- and post-intervention outcomes among individuals with non-ocular conditions such as dyslexia and Irlen syndrome and ocular conditions such as color vision deficiency (CVD) and cone-rod dystrophy (CRD).

Methodology

This prospective cohort study was conducted from 2016 to 2021 among cases (seven years or older) who were diagnosed with dyslexia, Irlen syndrome, CVD, or CRD. Participants were given a short questionnaire to read, followed by asking direct questions regarding medical health history, ocular history, eyeglasses prescription, and a full orthoptics evaluation. The main outcomes were the improvement in reading speed, reading accuracy, and visual stress.

Results

A total of 156 patients were included in this study; 110 patients with dyslexia, 19 with Irlen syndrome, 16 with CVD, and 11 with CRD. The findings showed that the reading speed and accuracy were improved in 96.34% of patients with dyslexia and 78.9% of patients with Irlen syndrome. The use of a chromagen lens was significantly associated with visual stress improvement in 89.8% of patients (p = 0.02). Photosensitivity was significantly improved after wearing the chromagen lenses in patients with CVD (87.5%) and CRD (63.6%).

Conclusions

The study findings showed a positive impact of chromagen lenses on reducing visual stress, including reading speed and accuracy, in patients with dyslexia and Irlen syndrome. Photosensitivity improved in patients with Irlen syndrome and CRD. Color vision was enhanced in patients with CVD. However, further studies are required to investigate the predictors of improvement and assess the long-term efficacy of chromagen lenses on daily activities and learning skills.

Effectiveness of Super Floss and Water Flosser in Plaque Removal for Patients Undergoing Orthodontic Treatment: A Randomized Controlled Trial

Objectives

This study aimed to compare the effectiveness of super floss and water flosser in plaque removal for patients undergoing orthodontic treatment.

Methods

A single-blind, randomized, controlled, parallel clinical trial with a split-mouth protocol was conducted on young adult orthodontic patients who were recruited from Riyadh Specialized Dental Center in Riyadh, Saudi Arabia. The type of floss used was randomly assigned to each side of the oral cavity; Super-Floss® (Oral-B) was used on one side, while the Waterpik® water flosser was used on the other. Patients' plaque level was assessed using Rustogi et al. modified navy plaque index (RMNPI) at baseline and immediately after cleaning.

Results

A total of 62 subjects were screened; however, only 34 subjects were enrolled in the study with an equal number of males and females. Overall, the plaque score was significantly reduced from 0.56 ± 0.35 to 0.13 ± 0.26 in the super floss group and from 0.61 ± 0.35 to 0.13 ± 0.28 in the water flosser group. There was no significant difference between the mean difference of super floss and water flosser (p=0.951). On the other hand, there was no significant difference between both groups in terms of the preintervention plaque score (p=0.379). The water flosser had a greater effect size on plaque removal compared to super floss on distal interproximal surface of the molar tooth with a mean difference of (−0.21, 95% CI: 00.37 to −0.04, p=0.033).

Conclusions

The use of super floss or water flosser as interproximal aids for plaque removal in patients undergoing orthodontic treatment are both effective. Trial registration. ISRCTN, ISRCTN83875016. Registered 12 September 2021-retrospectively registered, https://www.isrctn.com/ISRCTN83875016.

Viewing Strategies in Children With Visual Impairment and Children With Normal Vision: A Systematic Scoping Review

Viewing strategies are strategies used to support visual information processing. These strategies may differ between children with cerebral visual impairment (CVI), children with ocular visual impairment, and children with normal vision since visual impairment might have an impact on viewing behavior. In current visual rehabilitation practice a variety of strategies is used without consideration of the differences in etiology of the visual impairment or in the spontaneous viewing strategies used. This systematic scoping review focuses on viewing strategies used during near school-based tasks like reading and on possible interventions aimed at viewing strategies. The goal is threefold: (1) creating a clear concept of viewing strategies, (2) mapping differences in viewing strategies between children with ocular visual impairment, children with CVI and children with normal vision, and (3) identifying interventions that can improve visual processing by targeting viewing strategies. Four databases were used to conduct the literature search: PubMed, Embase, PsycINFO and Cochrane. Seven hundred and ninety-nine articles were screened by two independent reviewers using PRISMA reporting guidelines of which 30 were included for qualitative analysis. Only five studies explicitly mentioned strategies used during visual processing, namely gaze strategies, reading strategies and search strategies. We define a viewing strategy as a conscious and systematic way of viewing during task performance. The results of this review are integrated with different attention network systems, which provide direction on how to design future interventions targeting the use of viewing strategies to improve different aspects of visual processing.

The Relation between Physiological Parameters and Colour Modifications in Text Background and Overlay during Reading in Children with and without Dyslexia

Reading is one of the essential processes during the maturation of an individual. It is estimated that 5-10% of school-age children are affected by dyslexia, the reading disorder characterised by difficulties in the accuracy or fluency of word recognition. There are many studies which have reported that coloured overlays and background could improve the reading process, especially in children with reading disorders. As dyslexia has neurobiological origins, the aim of the present research was to understand the relationship between physiological parameters and colour modifications in the text and background during reading in children with and without dyslexia. We have measured differences in electroencephalography (EEG), heart rate variability (HRV), electrodermal activities (EDA) and eye movements of the 36 school-age (from 8 to 12 years old) children (18 with dyslexia and 18 of control group) during the reading task in 13 combinations of background and overlay colours. Our findings showed that the dyslexic children have longer reading duration, fixation count, fixation duration average, fixation duration total, and longer saccade count, saccade duration total, and saccade duration average while reading on white and coloured background/overlay. It was found that the turquoise background, turquoise overlay, and yellow background colours are beneficial for dyslexic readers, as they achieved the shortest time duration of the reading tasks when these colours were used. Additionally, dyslexic children have higher values of beta (15-40 Hz) and the broadband EEG (0.5-40 Hz) power while reading in one particular colour (purple), as well as increasing theta range power while reading with the purple overlay. We have observed no significant differences between HRV parameters on white colour, except for single colours (purple, turquoise overlay, and yellow overlay) where the control group showed higher values for mean HR, while dyslexic children scored higher with mean RR. Regarding EDA measure, we found systematically lower values in children with dyslexia in comparison to the control group. Based on the present results, we can conclude that both pastel and intense background/overlays are beneficial for reading of both groups and all sensor modalities could be used to better understand the neurophysiological origins in dyslexic children.

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.

Visual training could be useful for improving reading capabilities in dyslexia

The term dyslexia originated in 1887 when an ophthalmologist described the difficulty of learning to read. After more than a century of research, we still do not know the etiology of such pathology. Several hypotheses have been suggested to explain dyslexia and in the present article we will describe in detail the visual attentional deficits reported in dyslexia. Reading is a complex cognitive process during which several mechanisms are involved (visual perception, eye movements -saccades and fixations-, semantic and linguistic abilities); consequently, a deficit in one of these different components could cause impairment in reading acquisition. In children with dyslexia, we observed abnormal oculomotor patterns during reading: frequent saccades of small amplitude, long-term fixation, high number of saccades to the left (retro-saccades), and poor binocular coordination during and after the saccades. These results suggest a deficit of visual information processing as well as an immaturity of the interaction between the saccade and vergence systems. In the present review, we will discuss different methods that use short periods of visual rehabilitation or text manipulation, and by using an eye tracker in order to obtain objective information on eye movement's performance during reading, assist in improved reading performance of dyslexic children.

Effect of colored filters on reading capabilities in dyslexic children

AIM

The aim of the present study was to examine the effects of colored filters on reading performance and eye movement control in children with and without dyslexia.

METHODS

Eighteen children with dyslexia and 18 children without dyslexia were seated on a chair with their heads stabilized by a forehead and chin support. The children read different texts under the following three filter conditions: no filter, yellow filter, and green filter. The children's eye movements were recorded with a Mobile EyeBrain Tracker. Reading total time, duration of fixation between two successive saccades, pro-saccades amplitude and number of pro- and retro-saccades were obtained.

RESULTS

Children with dyslexia read the fastest and had the shortest fixation time in the green filter condition compared with the other conditions. Furthermore, children with dyslexia showed the shortest fixation time in the green filter condition with respect to the other conditions.

CONCLUSIONS

Taken together, these results suggested that the green filter improved reading performance in children with dyslexia because the filter most likely facilitated cortical activity and decreased visual distortions.

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.

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.

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.

Supporting Children with Visual Stress: The Development of a Web Resource for Parents and Professionals

Introduction

Visual stress is a condition which makes reading difficult. The use of coloured lenses in spectacles to alleviate the symptoms of visual stress has attracted increasing interest. The aim was to develop a web-based resource to centralize information about the condition and the processes for the screening, assessment, and provision of coloured lenses.

Method

Action research methods were employed. The exploratory phase used semi-structured interviews to gather parents' and professionals' views on the condition and their suggestions for the content and layout of a supporting web resource. The innovatory phase was used to design the prototype web resource. The evaluative phase was used to appraise and enhance the prototype website and collate data on website usage.

Results

Parents and professionals had some awareness of the condition but felt less sure of the evidence base for coloured lenses. Professionals valued research as evidence, whereas parents preferred testimonials. Suggestions for the content of a web resource to centralize information on the topic were clearly articulated by professionals, parents, and experts in the field. In the first year, over 7,500 individual web users visited the resource.

Conclusion

The first collaborative resource on the topic has been successfully produced, thereby offering a centralized information resource.

Dyslexia: the Role of Vision and Visual Attention

Dyslexia is more than just difficulty with translating letters into sounds. Many dyslexics have problems with clearly seeing letters and their order. These difficulties may be caused by abnormal development of their visual “magnocellular” (M) nerve cells; these mediate the ability to rapidly identify letters and their order because they control visual guidance of attention and of eye fixations. Evidence for M cell impairment has been demonstrated at all levels of the visual system: in the retina, in the lateral geniculate nucleus, in the primary visual cortex and throughout the dorsal visuomotor “where” pathway forward from the visual cortex to the posterior parietal and prefrontal cortices. This abnormality destabilises visual perception; hence, its severity in individuals correlates with their reading deficit. Treatments that facilitate M function, such as viewing text through yellow or blue filters, can greatly increase reading progress in children with visual reading problems. M weakness may be caused by genetic vulnerability, which can disturb orderly migration of cortical neurones during development or possibly reduce uptake of omega-3 fatty acids, which are usually obtained from fish oils in the diet. For example, M cell membranes require replenishment of the omega-3 docosahexaenoic acid to maintain their rapid responses. Hence, supplementing some dyslexics’ diets with DHA can greatly improve their M function and their reading.