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Irlen Syndrome and Behavioral Optometry

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Dr Kerry Hempenstall [Ph.D., B.Sc., Dip.Ed., Dip.Soc.Studies, Dip.Ed.Psych., MAPS]

“In education, there has long been a concern that there are students struggling with literacy. From time to time there has been an approach that claims they know of an element that improves such students. Promotors of such elements may not necessarily have evidence to support their claims. This paper considers such a situation with Irlen Syndrome and Behavioral Optometry.”



This paper addresses an involvement in education. I studied whether those programs were effective – back around 2020.



Why did I start another document?

I decided to take into account more recent literacy documents, and I’ve selected only newish research findings - provided in the years 2020 to 2025.

The idea was to get some sense whether the treatment had been popular or changed. The later document of mine had some older documents. This original material is still available in the later section of this document.

I decided to take into account older documents, and I’ve selected only newer research provided in the years 2020 to 2025.

My idea was to get some sense of how the technique in education may have changed or discontinued.



I expect these issues as my older document even then suggested there was only minimal activity in classroom benefits.



So here starts some of the up-to-date information. My original piece is at the end of the document.



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No scientific evidence that Irlen Syndrome exists, say ophthalmologists (2019)



“The Royal Australian and New Zealand College of Ophthalmologists (RANZCO) has released a hh explaining that there is no evidence that Irlen Syndrome exists and that there is no proof that supposed treatments, such as Irlen lenses, help those with reading difficulties.

“The real concern with diagnoses of Irlen Syndrome,” explains RANZCO spokesperson Prof Frank Martin, “is that it can distract from genuine diagnosis and treatment, such as a comprehensive evaluation by an educational psychologist followed by the appropriate remedial educational input. Any interventions that distract from and delay this evaluation could be detrimental to the effective treatment of any learning disabilities.”

Irlen Syndrome is commonly defined as a perceptual processing disorder, suggesting that the brain is unable to properly process visual information from the eyes because of sensitivity to certain wavelengths of light. Symptoms are said to include poor concentration; difficulties with reading, writing and comprehension; glare sensitivity; headaches and poor depth perception. RANZCO’s Irlen Syndrome position statement states that “Despite Irlen Syndrome being first described in the early 1980s, there is still no sound theoretical basis or evidence that the condition actually exists. A diagnosis of Irlen Syndrome is based solely on symptoms with no quantitative physiological correlation.”

Treatments associated with Irlen Syndrome such as coloured lenses have not been proven to be any more effective in improving reading difficulties in children than in children assessed in a control group (without coloured lenses and associated ‘treatments’). RANZCO’s Irlen Syndrome position statement explains that there is no documented evidence to say that Irlen lenses are harmful, but the use of unproven methods may waste time and financial resources preventing a child from receiving the appropriate evidence-based educational remedies that could actually help with their learning development.

Overwhelmingly the research shows no benefit from this treatment in children with reading difficulties and vulnerable parents are being exploited and having their children subjected to unnecessary screening practices,” said Prof Frank Martin.

RANZCO’s Irlen Syndrome position statement

RANZCO is also warning parents about other ineffective and unproven vision therapies being offered as supposed treatments for learning disabilities such as dyslexia.

As a medical education body supporting only evidence based treatments, RANZCO has an obligation to safe guard the interests of patients by speaking out against treatments that lack clinical or scientific merit,” explained RANZCO spokesperson A/Prof James Elder. “Ophthalmologists, like mainstream optometrists, are very passionate about saving sight and don’t like to see resources intended for health and wellbeing being misdirected. Reviews of the literature have consistently shown a lack of good evidence to support vision therapies, such as those offered by behavioural optometrists, for the treatment of learning disabilities such as dyslexia.

Using these expensive, ineffective and controversial treatments may delay a child from receiving the appropriate evidence-based educational remedies. Evidence shows that the earlier the intervention with the appropriate remedial programs, the more effective they are in improving reading outcomes. The use of ineffective interventions may also waste the limited financial resources of the family as well as giving them a false sense of security that the child’s reading difficulties are being addressed.

It is important, therefore, that parents understand that dyslexia and other learning disabilities are not disorders of vision and so, visual therapy is misdirected. Scientific evidence shows that behavioural optometry treatments such as eye tracking exercises, vision therapy, weak glasses to relax the focus, and coloured lenses/overlays do not help children read any better.

Eye care professionals such as ophthalmologists and optometrists are not qualified to diagnose or treat learning disabilities. However, children with learning difficulties will usually have both their hearing and vision assessed because listening and seeing are the first steps in information processing for the purpose of learning. The role of optometrists and ophthalmologists is therefore to diagnose and treat any treatable vision problems that may be contributing to any difficulties at school.”



The Royal Australian and New Zealand College of Opthalmologists.

Prof Frank Martin and A/Prof James Elder

https://ranzco.edu/news/no-scientific-evidence-that-irlen-syndrome-exists-say-ophthalmologists/



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Reading, Dyslexia, and Vision Therapy (2022)



Abstract

“Learning to read and write may be challenging for many children. In the USA, approximately 65% of children experience difficulty learning to read. Good literacy is an important social determinant of both physical and psychological health and is a large factor in final educational attainment, employment, income, and other socioeconomic outcomes. The causes of reading difficulty are multifactorial.

Dyslexia is a neurobiological language-based reading disability that is typically due to a deficit in phonological processing leading to trouble sounding out and recognizing words. Though it is often underrecognized, dyslexia affects up to 15–20% of children in the USA, to some degree.

Treatment of dyslexia is educational in nature. The International Dyslexia Association recommends that the “structured literacy” approach be implemented by well-trained educators. Because dyslexia and other learning disabilities are chronic conditions with no quick simple cure, they have spawned a wide variety of scientifically unsupported evaluations and treatments.

When parents are anxious to find solutions, friends, teachers, other health providers, or the media may suggest expensive and unproven treatments such as vision therapy or colored lenses or colored overlays.”



Handler, S.M., Granet, D.B. (2022). Reading, Dyslexia, and Vision Therapy. In: Albert, D.M., Miller, J.W., Azar, D.T., Young, L.H. (eds) Albert and Jakobiec's Principles and Practice of Ophthalmology. Springer, Cham. https://link.springer.com/referenceworkentry/10.1007/978-3-030-42634-7_285





SLPs’ perceptions of language learning myths about children who are DHH (Deaf or Hard of Hearing) (2023)



“The purpose of this exploratory study was to evaluate speech-language pathologists' (SLPs') conceptions and misconceptions about dyslexia.

Method:

Participants were 86 school-based SLPs. They completed an online survey on which they rated their agreement and disagreement with true and false statements related to the scientific evidence about the nature of dyslexia and interventions for dyslexia, as well as common misconceptions about dyslexia.

Results:

There was considerable variability among SLPs' agreement and disagreement with the statements. Critically, despite abundant contrary evidence in the literature, many SLPs believe that dyslexia involves a visual processing deficit.

Conclusions:

These findings suggest that many school-based SLPs hold misconceptions about dyslexia, especially those related to dyslexia being a visual disorder. The identified misconceptions may contribute to some SLPs' reluctance to incorporate reading and prereading skills into speech-language assessment and intervention. SLPs need greater knowledge of dyslexia to provide more effective evaluations and intervention services.”



Jena McDaniel, Hannah Krimm, C, Melanie Schuele, (2023). SLPs’ perceptions of language learning myths about children who are DHH, Journal of Deaf Studies and Deaf Education, 10.1093/deafed/enad043, 29, 2, (245-257).



What Do School-Based Speech-Language Pathologists Think About Dyslexia? (2023)



“Misconceptions about neurodevelopment and neurodevelopmental disorders abound among the public and educators alike, including speech-language pathologists (SLPs). The problem of misconceptions is pervasive and persistent; recent findings indicate that many neuromyths are as popular today as they were a decade ago (Dekker et al., 2012; Torrijos-Muelas et al., 2021).



Studies of neuromyths in education typically focus on a range of neuromyths across different aspects of brain function and define educators as a range of professionals involved in education (Torrijos-Muelas et al., 2021). Some of the most prevalent misconceptions relate to the signs and symptoms of dyslexia (Macdonald et al., 2017). The purpose of this exploratory study was to specifically examine school-based SLPs' beliefs about dyslexia.

Neuromyths in Education

There has been substantial interest in documenting belief in neuromyths. Macdonald et al. (2017) examined belief in neuromyths among a sample of almost 4,000 participants. Their sample included members of the public, neuroscience experts, and educators. “Educator” was broadly defined to include individuals working in early childhood education through higher education in a teaching role (special education and general education), administrative role (e.g., principals and deans), or related educational services (e.g., SLPs and counselors).

On a survey, participants marked a series of statements as true or false dichotomously. Although educators marked fewer neuromyths as true than the public did, they marked more than half (56%) of the myths as true.

Similar findings have been reported in several studies that specifically have examined educators' understanding of dyslexia (Gini et al., 2021; Wadlington & Wadlington, 2005; Washburn et al., 2011). Gini et al. (2021) reported high endorsement of neuromyths about dyslexia among the public and educators alike, with no statistically significant difference in endorsement of myths about dyslexia between individuals who had and had not worked with children with dyslexia. The belief in a visual basis for dyslexia seems particularly pervasive and persistent even though theories about a visual basis for dyslexia have long been disproven (see Vellutino et al., 2004, for a review). More than 90% of teachers in Washburn et al.'s (2011) sample agreed that “seeing letters and words backwards is a characteristic of dyslexia” (p. 174), and more than 70% of teachers in the sample agreed that “children with dyslexia can be helped by using colored lenses/colored overlays” (p. 174).

Causes and Characteristics of Dyslexia

A large body of literature demonstrates that dyslexia typically arises from a deficit in the phonological domain of language (Kovelman et al., 2012; Vellutino et al., 2004). Children with dyslexia routinely have deficits in phonological processing, which comprises phonological memory (i.e., ability to hold speech-based information in working memory), phonological retrieval (i.e., ability to retrieve speech-based information from long-term memory), and phonemic awareness (i.e., ability to segment, blend, and manipulate individual speech sounds). Poor performance on tasks that diagnostically tap any of these phonological processing skills may indicate dyslexia (Catts, 1989). Deficits in phonemic awareness precipitate difficulty with accurately and/or fluently decoding (i.e., reading) and encoding (i.e., spelling) written words (Melby-Lervåg et al., 2012; Snowling et al., 2020; Wagner & Torgesen, 1987).

Early identification and intervention for children with dyslexia can change their literacy trajectories. Phonemic awareness instruction in the early elementary years, especially when combined with systematic phonics instruction, has a substantial and lasting positive effect on reading acquisition (Ball & Blachman, 1988; Rehfeld et al., 2022). Dyslexia is less prevalent in the later grades among children who received explicit phonological awareness instruction in kindergarten compared to children who received no explicit phonological awareness instruction (Torgesen, 2000).

Dyslexia and Other Communication Disorders

Contrary to popular opinion, most definitions of dyslexia characterize it as difficulty with decoding and/or spelling that often is caused by difficulty with phonological processing (International Dyslexia Association, 2002; National Institute of Neurological Disorders and Stroke, 2023). Researchers generally agree that dyslexia can and often does co-occur with oral language impairment1 (hence, language impairment) and assert that both can be considered under the umbrella of developmental language disorders (Adlof & Hogan, 2018; Catts et al., 2005; McArthur et al., 2000; Werfel & Krimm, 2017).

For example, McArthur et al. (2000) synthesized the results of several studies of children who previously had been diagnosed with dyslexia or language impairment. Participants completed a language and literacy assessment battery that included evaluation of reading accuracy (i.e., decoding) using the Neale Analysis of Reading Ability–Revised (NARA-R; Neale, 1988) and evaluation of oral language abilities using the Clinical Evaluation of Language Fundamentals–Revised (CELF-R; Semmel et al., 1987).

McArthur et al. reported that more than half (55%) of the children who had been identified with dyslexia also met criteria for language impairment (CELF-R Total Language score < 85 in two studies, < 77 in one study) and that more than half (51%) of the children who had been identified with language impairment also met criteria for dyslexia (NARA-R scores at least 12–24 months below age expectations). These findings highlight the need for SLPs to be involved in identifying children with dyslexia, many of whom have co-occurring language impairment, agreement ratings, and percentage of the sample that provided a positive agreement rating for each statement. The mean agreement rating for the four true statements about dyslexia was 17.2 (S = 9.6). The mean agreement rating for the 10 false statements about dyslexia was −10.9 (SD = 13.4). Individual SLP ratings covered the entire scale range (i.e., −50 to +50) for all but four statements.

Causes and Characteristics of Dyslexia

Figure 2 illustrates the distributions of the agreement ratings for the five statements about the causes and characteristics of dyslexia. The frequencies of participant responses were grouped into 10 equal-sized bins of agreement ratings, plus a bin for agreement ratings of 0. The distributions of responses about causes and characteristics of dyslexia proceeded in the ideal direction for three statements. Responses clustered on the right half of the histogram, indicating tendency toward agreement, for the true statement: “Difficulty processing sounds in language is one of the major deficits found in dyslexia” (a on the figure). Responses clustered on the left half of the histogram, indicating tendency toward disagreement, for the false statement: “Dyslexia is primarily a visual-based disorder” (c on the figure) and for the false statement: “Students with dyslexia see words jumping around on the page” (e on the figure). However, responses clustered on the right half of the histogram for two false statements: “Visual Perceptual deficiencies are components of the dyslexia diagnosis” and “Seeing letters and words backwards is a characteristic of dyslexia” (b and d on the figure, respectively).

Instruction and Intervention for Children With Dyslexia

Three survey statements relate to instruction and intervention for children with dyslexia. See Figure 3. The majority (88%) of participants correctly agreed that students with dyslexia need explicit, systematic, direct instruction in phonemic awareness and phonics. However, an unsettling proportion of participants agreed that “Students with dyslexia should be taught how to read using the whole-word method” (20%) and that “Colored lenses and colored overlays are research-based accommodations for children with dyslexia” (21%).

Causes and Characteristics of Dyslexia

The majority of SLPs were aware that phonological processing difficulties, not visual deficits, are the primary cause of dyslexia. This awareness, however, has not replaced beliefs about a visual deficit as a causal mechanism; the majority of SLPs in the sample agreed that although visual–perceptual deficits are not a primary cause of dyslexia, they are a component of the dyslexia diagnosis. Additionally, the majority of SLPs agreed that seeing letters and words backward is a characteristic of dyslexia. Our findings are consistent with Washburn et al.'s (2011) findings among teachers and the lay population. Taken together, these findings suggest a persistent and pervasive misconception about visual deficits in dyslexia that needs to be corrected.

There are several potential challenges presented by the persistent belief that visual deficits cause dyslexia and that children with dyslexia experience visual symptoms. First, persistent belief that children with dyslexia see letters or words backward likely affects which children are referred for evaluation. Not only are letter reversals not characteristic of dyslexia, they are common among children who are acquiring reading and writing skills typically (Treiman et al., 2014). If a primary “red flag” that parents and teachers look for is, in fact, not a red flag at all, many children who present with actual red flags (e.g., phonemic awareness deficits and other spoken language difficulties but not letter reversals) may be overlooked for referral. SLPs need to ensure that parents and educators are aware that early language difficulties often precede identification of dyslexia (Catts, 1997).

Once a child is referred for evaluation for dyslexia, the persistent belief in visual–perceptual deficits may waste valuable assessment time. Although guidelines about what should be included in a dyslexia evaluation vary across settings, a comprehensive evaluation should include multiple measures to evaluate the child's strengths and weaknesses across linguistic domains (Adlof & Hogan, 2018).

In alignment with previous recommendations (e.g., Adlof & Hogan, 2018), we recommend that children with suspected dyslexia be evaluated using at least (a) a measure of phonological processing, (b) a measure of pseudoword reading, (c) a measure of reading fluency, and (d) a measure of spelling. However, because dyslexia and language impairment often co-occur, best practice would involve including spoken language measures suitable for assisting in the identification of language impairment in dyslexia evaluations (Adlof & Hogan, 2018). SLPs need to be aware of the high rate of co-occurrence and communicate with the special education team to ensure that spoken language skills are assessed appropriately. Doing so will ensure that children with co-occurring language impairment and dyslexia can be identified as such and provided with intervention that meets each child's needs, rather than with intervention that addresses only decoding difficulties.

In addition to a comprehensive evaluation of language skills, it also may be necessary for children with suspected dyslexia to be evaluated for other commonly co-occurring disorders such as attention-deficit/hyperactivity disorder, anxiety, and depression (Germanò et al., 2010; Mugnaini et al., 2009). Thus, a comprehensive evaluation for a child with dyslexia is likely to last several hours and involve multiple professionals. Spending time evaluating visual processing wastes time given that such deficits neither contribute to reading skills nor differentiate between children with and without dyslexia (Vellutino et al., 1991).

Finally, the persistent belief in visual processing deficits as a component of dyslexia may contribute to SLPs' concerns over whether they are qualified to diagnose or contribute to the diagnosis of dyslexia. Although there is considerable confusion around this issue and SLPs' role in diagnosing dyslexia may vary across states and clinical settings, SLPs are qualified to administer and interpret measures of phonological processing, reading, writing, and spoken language to diagnose dyslexia. ASHA (2001) specifically includes assessing and supporting written language as one of SLPs' roles and responsibilities. Countering the belief in a visual deficit in children with dyslexia while highlighting the linguistic nature of the disorder may support SLPs in advocating for their role on literacy teams.

Instruction and Intervention for Children With Dyslexia

The erroneous belief in a visual deficit in children with dyslexia also likely contributes to the continued popularity of sham therapies such as colored lenses, special fonts, and behavioral optometry (i.e., visual exercises; Hempenstall, 2020). The pattern of correlations in our data suggests that endorsement of visual interventions tends to occur alongside agreement with a visual basis for dyslexia. Indeed, ideally interventions are chosen according to the known or hypothesized origin of a disorder. However, a wealth of research shows that accommodations such as colored lenses and special fonts and interventions such as vision exercises are ineffective for treating dyslexia (Hempenstall, 2020). The resources spent procuring these products and services would be better spent securing access to effective instruction, intervention, and accommodations (e.g., audiobooks). Thus, it is important for professionals to encourage pursuit of evidence-based interventions that are likely to result in meaningful change.

Rather than seeking visual solutions to a linguistic problem, educators should provide early phonological awareness intervention for children with and at risk for dyslexia. Phonological awareness is a malleable skill that is improved with intervention (Al Otaiba et al., 2009), and improving phonological awareness is associated with improved reading outcomes (Torgesen, 2002). Because SLPs tend to outperform other educators on explicit phonological awareness tasks (Krimm, 2019; Spencer et al., 2008), delivering such intervention and partnering with classroom teachers to improve Tier 1 phonological awareness instruction are means by which SLPs can begin to integrate themselves within literacy teams (Catts, 1991; Girolametto et al., 2012).

Consequences of Misconceptions About Dyslexia

Although many SLPs correctly agreed with true statements about dyslexia and correctly disagreed with false statements about dyslexia, the relative strength of their agreement/disagreement is concerning. Ratings for true and false statements tended to converge toward the middle of the scale. These ratings suggest that SLPs who have accurate knowledge of dyslexia may lack confidence in their knowledge. Importantly, a lack of confidence may prevent an SLP from promoting evidence-based practice. For example, an SLP who knows that dyslexia results from a phonological processing deficit but who doubts their own understanding may not correct a parent or colleague whose comments suggest the belief that dyslexia results from a visual deficit.

The seemingly inescapable belief in a visual component to dyslexia, combined with a lack of conviction about the phonological basis of dyslexia, may also explain SLPs' apparent reluctance to address literacy and preliteracy skills in speech-language intervention. Clarifying that dyslexia is a linguistically based disorder that often co-occurs with language impairment (± speech impairment) may be an important starting point for encouraging SLPs to identify children at risk for dyslexia. Similarly, clarifying the powerful protective effect of early elementary phonological awareness instruction on later elementary reading achievement may nudge SLPs toward including phonological awareness in speech-language intervention and/or participating as interventionists in Tier 2 phonological awareness interventions.

SLPs are encouraged to seek scientifically sound information about dyslexia independently. A tarting point may be to read Peltier et al.'s (2020b) refutation text, which can be found here, https://doi.org/10.17605/OSF.IO/FBYHT, and/or to form a professional learning community based on Speech to Print: Language Essentials for Teachers (Moats, 2020), which details the connections between spoken and written language while providing in-depth information about the structures and functions of written English. SLPs who wish to seek additional coursework to prepare them to evaluate and treat children with dyslexia can access a list of programs accredited by the International Dyslexia Association here: https://dyslexiaida.org/accredited-teaching-training-programs/. Many programs are tailored to the needs of working educators and offer online classes and flexible scheduling. Other programs can be completed with intensive training over a few weeks, usually with the addition of a longer practicum experience.

Many people think dyslexia is a visual or perceptual difficulty [statement of misconception]… . But that is not what has been shown by research [explicit refutation]. In actuality, dyslexia is primarily a language-based reading disability, not a visual-based disability [replacement conception]… . Research shows that, in students with dyslexia, the part of the brain that processes…sounds and connects those sounds to letters is underactivated as compared with typically developing readers [description of support]. (p. 1)

Conclusions and Future Directions

This study adds to the knowledge base by exploring conceptions and misconceptions about dyslexia in a sample of school SLPs. Our findings suggest that many school-based SLPs hold misconceptions about dyslexia. One of the most prominent misconceptions was that dyslexia is, at least in part, a visual disorder. SLPs' misconceptions about dyslexia may contribute to their general reluctance to address reading and writing skills. Given that children with language impairment are at high risk for dyslexia, SLPs need to better understand the scientific evidence about causes, identification, and remediation for children with dyslexia.”



Krimm H, McDaniel J, Schuele CM. (2023). Conceptions and Misconceptions: What Do School-Based Speech-Language Pathologists Think About Dyslexia? Lang Speech Hear Serv Sch. 2023 Oct 2;54(4):1267-1281. doi: 10.1044/2023_LSHSS-22-00199. Epub 2023 Sep 6. PMID: 37672782; PMCID: PMC10721248.



Dyslexia-Specific Font: A Promised Solution but Is It Effective? (2021)


“Key Takeaways

Dyslexia-specific fonts are an outgrowth of theories of dyslexia that are not widely accepted today.
There is little evidence to support the use of dyslexia-specific fonts as tools to help students with dyslexia read better.
Investing time and money into dyslexia-specific fonts potentially diverts resources from effective and affordable evidence-based accommodations and materials.
Dyslexia is characterized by difficulties accurately and fluently reading words and spelling. Today the most widely accepted theory is that people with dyslexia have problems processing sounds within words and connecting these sounds to letters. But other theories have been proposed over the years, with the most popular focusing on vision. One of the most common has been that people with dyslexia do not see letters as typical readers do. Instead, the letters might appear reversed or move around when they attempt to read. At one point, some people with dyslexia were given colored overlays or glasses with tinted lenses to remediate the problem, an approach whose effectiveness has been disproven by research. (For a detailed review of this approach, please read the article “Behavioral Optometry and Irlen Lenses to Resolve Reading Problems” in the Winter 2020 issue of Perspectives on Language and Literacy.)

Based on visual theories of dyslexia, dyslexia-specific fonts have emerged as a potential tool to help students with dyslexia read better. Parents and educators often ask us about these fonts and how well they work.

Here are the most common questions we receive:

Why might dyslexia-specific fonts matter?
What features of dyslexia-specific fonts make them different from other fonts?
Are dyslexia-specific fonts an effective accommodation for students with dyslexia?
Of course, No. 3 is the burning question and the short answer is no. But understanding the “why” and the “what” behind dyslexia-specific fonts helps to put “how effective” in context. We answered these questions by reviewing the information made available on developers’ websites and studies of dyslexia-specific fonts published in peer-reviewed journals (see Table 1).

Why might dyslexia-specific fonts matter?
All of this matters because parents and teachers have limited time, and schools have limited budgets and resources. They need accommodations and materials that are effective for students with dyslexia. When parents and teachers spend time and money on ineffective accommodations and materials, they take those resources away from other materials and methods that could be effective. So, if there are effective solutions that are low cost and easy to implement, we need to know about them and support their use.



What features of dyslexia-specific fonts make them different from other fonts?
Dyslexia-specific fonts tend to have bolder lines. They tend to have more spacing between the letters within a word. In addition, they tend to increase the spacing between words. Changing existing fonts to reduce the spacing between letters within words is detrimental to all readers. Moreover, research shows that increasing the distance between letters within words without also increasing the space between words results in decreased reading performance for all readers.

Examples:

The sun was bright.

(Arial 12-point font with added spacing)

The sun was bright.

(Comic Sans MS 12-point font with added spacing)

The sun was bright.

(OpenDyslexic 12-point font)

The sun was bright.

(Arial 12-point font no spacing added)

The sun was bright.

(Comic Sans MS 12-point font no added spacing)

The sun was bright.

(OpenDyslexic decreased spacing like typical font)

In addition, most dyslexia fonts were designed to reduce visual resemblance between letters commonly reversed, such as b and d. Moreover, some dyslexia fonts were designed to be visually heavier at the bottom of the letters to give them visual weight to keep them grounded.

These features are intended to address the misconception that individuals with dyslexia see letters backward or jumping around on the page. Although reversals are widely thought to be a hallmark of dyslexia, they are commonly observed in individuals who have not been exposed to a great deal of text, such as young children.

Is a dyslexia-specific font an effective accommodation for students with dyslexia?
The findings across the studies we reviewed did not provide evidence that a dyslexia-specific font would be an effective accommodation for students with dyslexia. People with dyslexia can overcome their struggles to read with proper interventions, including explicit instruction, modeling, continued exposure to text, and practice. However, by only changing the font of the text, readers were not able to read words better. Individual readers might prefer a certain font, but based on our review of published research, a particular font does not help individuals with dyslexia read better.

Considering the research on dyslexia fonts, there is limited support for investing time and resources to make these available for students with dyslexia. If a student has a preference, that is one thing. But there is no reason to believe that a dyslexia font is necessary for students with dyslexia to aid them with reading more fluently or accurately. The research on reading fatigue and eye strain is not as robust as the research exploring reading accuracy and fluency. However, there is also no compelling evidence we are aware of to suggest that these fonts are beneficial in these ways either.”



Pamela R. Shewalter & Timothy N. Odegard (2021). Dyslexia-Specific Font: A Promised Solution but Is It Effective?

https://dyslexialibrary.org/ida-newsletter/fall-2021/#two





Irlen lenses is of no use for reading problems and dyslexia. (2025)

“Irlen lenses are coloured spectacles proposed to help children or adults with reading problems. The lenses are chosen as a result of a guided trial and error process supervised by an Irlen lens franchise holder. However, reading difficulties can range from mild to severe to dyslexia, are often caused by a number of factors in combination, and are rarely due to one cause alone. The Australasian College of Behavioural Optometrists (ACBO) advises there is no reliable scientific evidence to support the routine use of Irlen lenses primarily to treat reading problems and dyslexia.



Australasian College of Behavioural Optometrists.

https://www.acbo.org.au/professionals/menu/news/238-acbo-position-statement-irlen-lenses#:~:text=The%20Australasian%20College%20of%20Behavioural,treat%20reading%20problems%20and%20dyslexia.





AI Overview



“Yes, it is widely understood that both Behavioral Optometry and Irlen Lenses are generally considered ineffective for addressing reading difficulties, particularly those associated with dyslexia. Scientific evidence and professional consensus suggest that they are not supported by strong research and may not provide a true solution for reading problems.

Here's why:

Lack of Evidence:
Numerous systematic reviews and studies have shown no significant benefit from treatments like behavioral vision therapy, eye muscle exercises, or colored lenses/overlays in improving reading performance.

Potential for Harm:
The Royal Australian and New Zealand College of Ophthalmologists (RANZCO) cautions that these treatments can delay access to evidence-based interventions and educational supports, potentially hindering effective treatment of learning disabilities.

Misdiagnosis and Exploitation:
Some, like the RANZCO, have voiced concerns that diagnoses like Irlen Syndrome can distract from proper evaluation by educational psychologists and lead to unnecessary screening practices and the exploitation of vulnerable families.

Focus on Educational Interventions:
The emphasis is on evidence-based educational interventions and strategies to improve reading skills, rather than vision therapy or colored lenses.



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So, having concluded the above documents, we go now to my early study below:



Behavioral Optometry and Irlen Lenses to Resolve Reading Problems (2020)

https://cdn.coverstand.com/13959/655062/c0ee0670a91c107f14581505c3b77d1335b1cc67.10.pdf



“Learning to read in the English language is particularly difficult, comprising a mix of several languages that employ different spelling conventions. Yet, reading is very highly valued in modern civilization, and much effort is expended in attempting to discover why an unacceptably high number of students fail to master the skills involved in reading.

Although there has been much research on how to teach reading, another direction has involved attempting to determine the processes underlying skilled reading, and then designing interventions to develop those skills directly. One such domain involves visual processes. If a child displays a problem with reading, it sounds at least plausible that vision may be the source of the problem. Indeed, extreme levels of visual disability can preclude conventional reading.

But, what about those struggling with reading whose visual problems are adequately corrected with optometric lenses, and those whose reading progress is of concern, but whose vision is considered within the normal range by conventional optometric assessment? Might there be some other vision problems not assessed or detected in this way that cause reading problems? The history of education is littered with claims of resolving educational problems by directly modifying processes that are presumed to be central to reading, for example, visual perception, balance, primitive reflexes, auditory processing speed, perceptual motor skills, brain patterns, auditory memory, and so on. Some are decidedly distal from the activity of reading, while others have more proximal links.

Reading is a complex behaviour, and the idea of intervening at a simple level to produce a complex effect is appealing. Generally speaking, the direct teaching of underlying processes has not improved reading (Fletcher et al., 2011; Arter & Jenkins, 1979). In some cases, the interventions didn’t improve the underlying processes. In other cases, the underlying processes improved, but reading skills did not.

In still others, there were difficulties in accurately assessing the processes and/or teaching them effectively. Further, weaknesses in these processes were also found among skilled readers. There has been a long search for a holy grail that removes the obstacle to learning such that reading attainment will then occur. If one could be discovered, then time-consuming, explicit instruction in reading would become less necessary for those who currently struggle to learn to read. Unfortunately, the underlying process approach has thus far represented an educational cul-de-sac.

Fuchs, Hale, and Kearns (2011) reviewed the evidence generally for such cognitively focused aptitude-treatment interactions. They concluded that treating a cognitive deficit in order to enhance a life skill such as reading has no substantial evidential support thus far; however, it is possible that some future cognitively focused interventions will be shown to be valuable. They concluded that an array of strong empirical, independent evidence is necessary, but not as yet available.

To provide ineffective interventions has serious negative implications for struggling students. Even if the interventions are otherwise non-harmful, there is an opportunity cost for students (and often a financial cost to parents), and a residue of negative emotion for both parents and child when the approach has no discernible effect.

Just because apparent visual skills deficits co-occur with dyslexia doesn’t mean they cause dyslexia. Additionally, it is possible that both dyslexia and visual skills deficits are caused by a third variable. There are two major areas of interest in judging whether an intervention has merit. The first is to consider whether the theoretical constructs behind the intervention are consistent with what is accepted knowledge about a given educational issue (i.e., face validity). This is not a perfect criterion, as occasionally a new paradigm makes earlier theories obsolete. However, that is relatively rare.

In the case of the various approaches that implicate vision problems as the cause of reading problems, one would acknowledge that they sound plausible (to a greater or lesser degree). Indeed, the early history of reading research emphasized a visual-based over the current language-based causation.

The second criterion goes beyond the theoretical relevance, and is the issue of whether addressing the reading problem by intervening at the visual level has a positive impact. So, it becomes then an empirical issue, rather than a purely theoretical one. The reading process requires complex eye movements. Rather than moving smoothly across a line of print, eyes travel in short staccato-like jerks called saccades (covering about eight letter spaces usually), followed by brief fixations (250 ms) during which we gain visual information (Clifton et al., 2016). It’s easy to envisage problems occurring for some students in this complex visuo-perceptual coordination task, not to mention the impact of the complexity involved in fluent orthographic processing. Further complicating reading is the fact that humans do not have a dedicated brain module for reading — “rather (it is) the result of a neuronal recycling from an area of the brain that evolution has dedicated to the recognition of certain forms, notably intersections of straight lines or curves” (Quercia, Feiss, & Michel, 2013, p. 873).

Researchers have noted numerous visual skills in which a proportion of students diagnosed with dyslexia have been shown to be deficient. The list includes: perception of low contrast, low spatial frequency and orientation, high frequency temporal visual information, and short visual attention span (Quercia et al., 2013). Vellutino and Fletcher (2005) also described some low-level visual deficits, such as visual tracking, convergence problems, and weakness of the magnocellular system.

Such a list of apparent deficits seems legitimate; however, just because they co-occur with dyslexia doesn’t mean they cause dyslexia. Additionally, it is possible that both dyslexia and visual skills deficits are caused by a third variable. So, the presence of a range of visual problems among struggling readers does not of itself mean that they cause reading problems. Although significant visual differences have been found between dyslexic and normally developing readers, only about 30% of dyslexics are so affected (Ramus et al., 2003).

One can find some of these visual processing deficits among skilled readers, too, which implies that the visual processing deficit is not the defining characteristic of dyslexia. The identified oculomotor anomalies are considered by the majority of researchers to be secondary to difficulties of cognitive analysis of language (Quercia et al., 2013; Vaughn & Linan-Thompson, 2003).

Another finding regarding dyslexic readers’ eye movements was that their focus frequently shifted back to the left along the text line instead of to the right (i.e., regression). The product of this faulty logic was that a lot of children wasted potential instructional time with eye exercises. However, research has shown that resolving reading problems through effective teaching caused excessive regressive eye movements to cease. Regressive eye movements do not cause reading problems, but are instead a consequence of reading problems. The two main interventions for dyslexia that emphasize the treatment of visual deficits are behavioral optometry and Irlen lenses. Proponents for each claim that the focus of their interventions directly impacts reading development.

Behavioral Optometry The criticisms of behavioral optometry treatments for dyslexia are extensive and include, among others, the absence of well-designed studies (Barrett, 2009); failure of studies to produce evidence of visual processing being causal to reading difficulties (Vellutino, Fletcher, Snowling, & Scanlon, 2004); varied definitions of dyslexia and assessment techniques (Schulte-Körne & Bruder, 2010); absence of reliable effects on reading of behavioral optometry interventions (National Health & Medical Research Council of Australia, 2009; Rawstron, Burley, & Elder, 2005); and unestablished validity and reliability of tests of accommodation, convergence, and eye tracking (Larson, 2018).

The scientific consensus is that learning to read is either unrelated to magnocellular disturbance (American College of Ophthalmologists, 2009; Birch & Chase, 2004; Shelley-Tremblay, Syklawer, & Ramkissoon, 2011), or is followed by changes in the magnocellular system, and not vice versa (Georgiou, Papadopoulos, Zarouna, & Parrila, 2012).

Furthermore, not all students with dyslexia have these deficits (Ramus et al., 2003), and some typically developing readers apparently do (Creavin, Lingam, Steer, & Williams, 2015; Quercia et al., 2013). For example, in the Creavin et al. study of 5,822 students, 80% of the dyslexia cohort displayed normal ophthalmic results in each of the tests involved.

Relevant major national bodies actively discourage the use of behavioral optometry for educational interventions (Handler & Fierson, 2011; National Health & Medical Research Council of Australia, 2009; Royal Australian and New Zealand College of Ophthalmologists, 2016).

Studies reporting that short-term prism correction aided reading likely are manifestations of placebo as the effect appears to be ephemeral (Chung & Borsting, 2018). In contrast to the lack of evidence for visual intervention, instruction in phonics, word analysis, reading fluency, and comprehension for dyslexia has an acknowledged positive impact (Galuschka, Ise, Krick, & Schulte-Korne, 2014; Hyatt, Stephenson, & Carter, 2009; Stein, 2015). The consensus among independent researchers is that vision-based treatment for academic problems, and in particular, dyslexia, does not have the evidence base to support its use. In an evidence-based practice era of education, it would not be in students’ best interests to use behavioral optometry to address reading difficulties. The consensus among independent researchers is that vision-based treatment for academic problems, and in particular, dyslexia, does not have the evidence base to support its use. Scotopic Sensitivity and Irlen Lens

Helen Irlen was a psychologist working with adults with reading difficulties during the 1980s. She believed that she had detected a visual stress problem in many of these adults that involved undue sensitivity to particular light frequencies. The frequencies varied among the individuals, and she developed assessment intended to determine which frequencies were problematic for each client. She named the condition scotopic sensitivity syndrome (SSS), and began to prescribe coloured lenses, either as eyeglasses or as overlays, to reduce this visual stress. She described a variety of visual sensations reported by clients as print that ran down the page like a river, blurriness, and words flickering, floating, or sliding off the page (Chouinard, Zhou, Hrybousky, Kim, & Cummine, 2012).

The success or otherwise of the prescribed overlay or glasses was determined by the subjective response of the client as to whether they believed a particular hue was helpful in alleviating their symptoms and enhancing their reading. This approach to evaluation produces its own problems, such as novelty and placebo (Galuschka, Ise, Krick, & Schulte-Korne, 2014). Additionally, Irlen asserted that a precise colour is needed to treat Irlen Syndrome. One would anticipate that the choice of colour would be similar if a person was re-assessed. However, Suttle, Barbur, and Conway (2017) observed that only one-third of candidates chose the same colour overlay on re-assessment at 25 days. Further, there was a gender issue reported by Conway, Evans, Evans, and Suttle (2016).

More males preferred stereotypical male colour lenses (blue and green), whereas females mainly preferred stereotypical female colours, such as pink and purple. Griffiths, Taylor, Henderson, and Barrett (2016) concluded there was a high false positive rate for Irlen Syndrome using these scales. They also reported a high rate of discontinuation of treatment: 63% had ceased wearing the lenses after three weeks. The internal validity and reliability of the Irlen assessment scales have not been published in any refereed journal. The use of Irlen lenses and overlays is discouraged by the relevant official bodies because of the absence of theoretical salience, contentious assessment tools, poor research design, and an absence of clear empirically supported student reading outcomes.

Scotopic sensitivity and Irlen lenses and overlays were enthusiastically and uncritically endorsed by many lay audiences, including the media. And, it remains accepted as a valuable treatment for dyslexia by many teachers (Bain, Brown, & Jordan, 2009; Washburn, Mulcahy, Joshi, & Binks-Cantrell, 2016).

However, the approach has been and remains controversial in the research community, both because it has been argued that no such syndrome exists (American Optometric Association, 2003), and that the treatment has not been demonstrated to be effective in well-designed studies (Griffiths et al., 2016; Iovino, Fletcher, Breitmeyer, & Foorman, 1998; Ritchie, Sala, & McIntosh, 2011; Suttle, Lawrenson, & Conway, 2018). Further compromising the educational relevance of SSS is that scotopic sensitivity has also been reported among typically developing readers (Lopez, Yolton, Kohl, Smith, & Saxerud, 1994).

Decades of well-designed studies have failed to demonstrate a beneficial impact of this approach to reading. Conversely, the quality of supportive research has been generally inadequate, and numerous studies that reported benefit have methodological weaknesses. For example, effects reported in studies in which there was no active control group disappeared when a placebo control group was employed (Elliot & Wood, 2017; Galuschka, Ise, Krick, & Schulte-Korne, 2014). A meta-analysis that included randomized controlled trials was generally negative (Albon, Adi, & Hyde, 2008; Suttle, Lawrenson, & Conway, 2018). In a 2016 systematic review of the literature, Griffiths et al. noted high levels of risk of bias in many studies, and the lower risk studies tended to offer less support for beneficial effects. This led them to conclude that any positive effects are most likely due to placebo, practice, or Hawthorne effects.

As with behavioral optometry, the use of Irlen lenses and overlays is discouraged by the relevant official bodies because of the absence of theoretical salience, contentious assessment tools, poor research design, and an absence of clear empirically supported student reading outcomes (American Academy of Ophthalmology, 2009; Handler, Fierson, and American Academy of Pediatrics, & the Section on Ophthalmology and Council on Children with Disabilities, American Academy of Ophthalmology, American Academy for Pediatric Ophthalmology and Strabismus, and American Association of Certified Orthoptists, 2011; National Health & Medical Research Council of Australia, 2009; Royal Australian and New Zealand College of Ophthalmologists, 2016). Nonetheless, Irlen lenses and overlays still continue to be heavily promoted as a worthy treatment for dyslexia, despite insufficient evidence that their use improves the reading skills of low progress readers.”



References

Albon, E., Adi, Y., & Hyde, C. (2008). The effectiveness and cost-effectiveness of coloured filters for reading disability: A systematic review. DPHE Report No. 67. Birmingham, UK: West Midlands Health Technology Assessment Collaboration (WMHTAC).



American Academy of Ophthalmology. (2009). Learning disabilities, dyslexia, and vision – A joint statement of the American Academy of Pediatrics, American Association for Pediatric Ophthalmology and Strabismus and American Academy of Ophthalmology. Retrieved from https://www.aao.org/clinical-statement/joint-statement-learning-disabilities-dyslexia-vis American



College of Ophthalmologists. (2009). Policy Statement: Learning Disabilities, Dyslexia and Vision. San Francisco, CA: American Academy of Ophthalmology.

American Optometric Association. (2003). The use of tinted lenses for the treatment of dyslexia and other related reading and learning disorders. Retrieved from http://web.archive.org/web/20000226214742/http://aoanet.org:80/ia-tinted.html

Arter, J. A., & Jenkins, J. R. (1979). Differential diagnosis—Prescriptive teaching: A critical appraisal. Review of Educational Research, 49, 517–555.

Bain, S. K., Brown, K. S., & Jordan, K. R. (2009). Teacher candidates’ accuracy of beliefs regarding childhood interventions. The Teacher Educator, 44(2), 71–89. Barrett, B. T. (2009). A critical evaluation of the evidence supporting the practice of behavioural vision therapy. Ophthalmic and Physiological Optics, 29, 4–25.

Birch, S., & Chase, C. H. (2004). Visual and language processing deficits in compensated and uncompensated college students with dyslexia. Journal of Learning Disabilities, 37, 389–412.

Chouinard, B. D., Zhou, C. l., Hrybousky, S., Kim, E. S., & Cummine, J. (2012). A functional neuroimaging case study of Meares-Irlen syndrome/visual stress (MISViS). Brain Topography, 25, 293–307.

Chung, A. G., & Borsting, E. (2018). The impact of short-term prism correction in convergence insufficiency on reading rate and accuracy. Optometry & Visual Performance, 6(1), 11–18. Clifton, C. E.,

Ferreira, F., Henderson, J. M., Inhoff, A. W., Liversedge, S., Reichle, E. D., & Schotter, E. R. (2016). Eye movements in reading and information processing: Keith Rayner’s 40 year legacy. Journal of Memory and Language, 86, 1–19.

Conway, M. L., Evans, B. J., Evans, J. C., & Suttle, C. M. (2016). Does gender influence colour choice in the treatment of visual stress? PLoS ONE, 11(9), e0163326. www.DyslexiaIDA.org Perspectives on Language and Literacy Winter 2020 19

Creavin, A. L., Lingam, R., Steer, C., & Williams, C. (2015). Ophthalmic abnormalities and reading impairment. Pediatrics, 135(6), 1057–1065.

Elliot, D. B., & Wood, J. M. (2017). Coloured filters show gender differences and poor repeatability. Ophthalmic and Physiological Optics, 37, 635–639.

Fletcher, J. M., Stuebing, K. K., Barth, A. E., Denton, C. A., Cirino, P. T., Francis, D. J., & Vaughn, S. (2011). Cognitive correlates of inadequate response to intervention. School Psychology Review, 40, 3–22.

Fuchs, D., Hale, J. B., & Kearns, D. M. (2011). On the importance of a cognitive processing perspective: An introduction. Journal of Learning Disabilities, 44(2), 99–104.

Galuschka, K., Ise, E., Krick, K., & Schulte-Korne, G. (2014). Effectiveness of treatment approaches for children and adolescents with reading disabilities: A meta-analysis of randomized controlled trials. PLoS ONE, 9(2): e89900. https://doi.org/10.1371/ journal.pone.0089900

Georgiou, G. K., Papadopoulos, T. C., Zarouna, E., & Parrila, R. (2012). Are auditory and visual processing deficits related to developmental dyslexia? Dyslexia, 18, 110–129. Griffiths, P. G., Taylor, R. H.,

Henderson, L. M., & Barrett, B. T. (2016). The effect of coloured overlays and lenses on reading: A systematic review of the literature. Ophthalmic & Physiological Optics, 36, 519–544. https://doi.org/10.1111/ opo.12316

Handler, S. M., & Fierson, W. M., American Academy of Pediatrics, & the Section on Ophthalmology and Council on Children with Disabilities, American Academy of Ophthalmology, American Academy for Pediatric Ophthalmology and Strabismus, and American Association of Certified Orthoptists. (2011). Joint technical report— Learning disabilities, dyslexia, and vision. Pediatrics, 127, 818–856.

Hyatt, K. J., Stephenson, J., & Carter, M. (2009). A review of three controversial educational practices: Perceptual motor programs, sensory integration, and tinted lenses. Education and Treatment of Children, 3, 313–342.

Iovino, I., Fletcher, J. M., Breitmeyer, B. G., & Foorman, B. R. (1998). Colored overlays for visual perceptual deficits in children with reading disability and attention deficit/hyperactivity disorder: Are they differentially effective? Journal of Clinical and Experimental Neuropsychology, 20, 791–806.

Larson, S. A. (2018). Is oculomotor testing important in developmental dyslexia? JAMA Ophthalmology,36, 1096–1097. https://doi.org/10.1001/jamaophthalmol.2018.2805

Lopez, R., Yolton, R. L., Kohl, P., Smith, D. L., & Saxerud, M. H. (1994). Comparison of Irlen scotopic sensitivity syndrome test results to academic and visual performance data. Journal of American Optometric Association, 65, 705–714.

National Health & Medical Research Council of Australia. (2009). Alternative therapies for ADHD. Retrieved from https://mental-health-matters.com/alternativetherapies-for-adhd/

Quercia, P., Feiss, L., & Michel, C. (2013). Developmental dyslexia and vision. Clinical Ophthalmology, 7, 869–881.

Ramus, F., Rosen, S., Dakin, S. C., Day, B. L., Castellote, J. M., White, S., & Frith, U. (2003). Theories of developmental dyslexia: Insights from a multiple case study of dyslexic adults. Brain, 126, 841–865.

Rawstron, J. A., Burley, C. D., & Elder, M. J. (2005). A systematic review of the applicability and efficacy of eye exercises. Journal of Pediatrics, Ophthalmology, and Strabismus, 42, 82–88.

Ritchie, S. J., Sala, S. D., & McIntosh, R. D. (2011). Irlen colored overlays do not alleviate reading difficulties. Pediatrics, 128, 932–938.

Royal Australian and New Zealand College of Ophthalmologists. (2016). Role of the ophthalmologist in the management of dyslexia. Eye2Eye Spring 2016 Feature. Retrieved from https://ranzco.edu/blog/eye2eye-spring-2016-feature-article/

Schulte-Körne, G., & Bruder, J. (2010). Clinical neurophysiology of visual and auditory processing in dyslexia: A review. Clinical Neurophysiology, 121, 1794–1809.

helley-Tremblay, J. F., Syklawer, S., & Ramkissoon, I. (2011). The effects of magno-parvocellular integration training on fluency and visual provoked potentials in poor readers. Journal of Behavioral Optometry, 22, 31–37.

Stein, M. T. (2015). Visual training methods are ineffective for dyslexia. New England Journal of Medicine: Journal Watch, June 2, 2015. Retrieved from http://www. jwatch.org/na38060/2015/06/02/visual-training-methods-are-ineffective-dyslexia Suttle, C. M.,

Lawrenson, J. G., & Conway, M. L. (2018). Efficacy of coloured overlays and lenses for treating reading difficulty: An overview of systematic reviews. Clinical and Experimental Optometry, 101, 514–520. https://doi.org/10.1111/cxo.12676

Vaughn, S., & Linan-Thompson, S. (2003). What is special about special education for students with learning disabilities? Journal of Special Education, 37, 140–147.

Vellutino, F. R., & Fletcher, J. M. (2005). Developmental dyslexia. In M. J. Snowling & C. Hulme (Eds.), The science of reading: A handbook (pp. 362–378).

Maldon, MA: Blackwell Publishing. Vellutino, F. R., Fletcher, J. M., Snowling, M. J., & Scanlon, D. M. (2004). Specific reading disability (dyslexia): What have we learned in the past four decades? Journal of Child Psychology and Psychiatry, 45(1), 2–40.

Washburn, E. K., Mulcahy, C. A., Joshi, M. R., & Binks-Cantrell, E. (2016). Teacher knowledge of dyslexia. Perspectives on Language and Literacy, 42(4), 9–13.



Now some more of relevant studies, but these are more recent than my original studies’ papers.



American Speech-Language-Hearing Association. (2021). 2020 member affiliate profile. https://www.asha.org/siteassets/surveys/2002-2022-member-and-affiliate-profile-trends.pdf



Byrom, B., Elash, C. A., Eremenco, S., Bodart, S., Muehlhausen, W., Platko, J. V., Watson C., & Howry C. (2022). Measurement comparability of electronic and paper administration of visual analogue scales: A review of published studies. Therapeutic Innovation & Regulatory Science, 56(3), 394–404. 10.1007/s43441-022-00376-2 [DOI] [PMC free article] [PubMed] [Google Scholar]



Krimm, H. (2019). An exploration of educator linguistic knowledge and expertise [Doctoral dissertation, Vanderbilt University]. Electronic Theses and Dissertations. https://etd.library.vanderbilt.edu/etd-03202019-154557 [Google Scholar]



Loveall, S. J., Pitt, A. R., Rolfe, K. G., & Mann, J. (2022). Speech-language pathologist reading survey: Scope of practice, training, caseloads, and confidence. Language, Speech, and Hearing Services in Schools, 53(3), 837–859. 10.1044/2022_LSHSS-21-00135 [DOI] [PubMed] [Google Scholar]



Dahhan, N. Z., Mesite, L., Feller, M. J., & Christodoulou, J. A. (2021). Identifying reading disabilities: A survey of practitioners. Learning Disability Quarterly, 44(4), 235–247. 10.1177/0731948721998707 [DOI] [Google Scholar]



Daniel, J., Krimm, H., & Schuele, C. M. (2023). Speech-language pathologists' endorsement of speech, language, and literacy myths reveals persistent research-practice gap. Language, Speech, and Hearing Services in Schools, 54(2), 550–568. 10.1044/2022_LSHSS-22-00087 [DOI] [PMC free article] [PubMed] [Google Scholar]



Moats, L. C. (2020). Speech to print: Language essentials for teachers (3rd ed.). Brookes. [Google Scholar]



National Institute of Neurological Disorders and Stroke. (2023). Dyslexia. Retrieved April 26, 2023, from https://www.ninds.nih.gov/



Peltier, T. K., Heddy, B. C., & Peltier, C. (2020). Dyslexia knowledge questionnaire. 10.17605/OSF.IO/8AYVX [DOI]



Peltier, T. K., Heddy, B. C., & Peltier, C. (2020). Refutation text. 10.17605/OSF.IO/FBYHT [DOI]



Peltier, T. K., Heddy, B. C., & Peltier, C. (2020). Using conceptual change theory to help preservice teachers understand dyslexia. Annals of Dyslexia, 70(1), 62–78. 10.1007/s11881-020-00192-z [DOI] [PubMed] [Google Scholar]



Snowling, M. J., Hulme, C., & Nation, K. (2020). Defining and understanding dyslexia: Past, present, and future. Oxford Review of Education, 46(4), 501–513. 10.1080/03054985.2020.1765756 [DOI] [PMC free article] [PubMed] Google Scholar



Rehfeld, D. M., Kilpatrick, M., O'Guinn, N., & Renbarger, R. (2022). A meta-analysis of phonemic awareness instruction provided to children suspected of having a reading disability. Language, Speech, and Hearing Services in Schools,53(4),1177–1201. 10.1044/2022_LSHSS-21-00160 [DOI] [PubMed] [Google Scholar]



Watson, M., O'Keefe, C., Wallace, A., & Terrell, P. (2020). A survey of reading teachers: Collaboration with speech-language pathologists. Perspectives of the ASHA Special Interest Groups, 5(1), 304–313. 10.1044/2019_PERSP-19-00006 [DOI] [Google Scholar]