Meares-Irlen Syndrome/Visual Stress (MISViS)

From EyeWiki

MISViS is a visual-processing disorder with a history of controversy with American and Australian/New Zealand Ophthalmology organizations.

Disease Entity

Meares-Irlen syndrome/visual stress (“MISViS”), also known as Meares-Irlen syndrome, Irlen syndrome, scotopic sensitivity syndrome or visual stress, is described as a visual-processing disorder characterized by difficulty with reading. MISViS was initially believed to be a subset of dyslexia; however, studies have suggested different cognitive etiology leading to controversy surrounding the condition[1]


The entity of MISViS was first characterized in the early 1980s, individually by Helen Irlen and Olive Meares.

Controversial Aspects of MISViS

In a joint position statement by the American Academy of Pediatrics (AAP), American Academy of Ophthalmology (AAO), and American Association for Pediatric Ophthalmology and Strabismus (AAPOS) concluded the following in July 2014 reaffirmed their 1984 statement[2]:

  • “Scientific evidence does not support the efficacy of eye exercises, behavioral vision therapy, or special tinted filters or lenses for improving the long-term educational performance in these complex pediatric neurocognitive conditions. Diagnostic and treatment approaches that lack scientific evidence of efficacy, including eye exercises, behavioral vision therapy, or special tinted filters or lenses, are not endorsed and should not be recommended.”
  • “Many of the studies that have been cited as proof of Irlen-lens efficiency have actually been inconclusive after deeper analysis. The evidence does not support the effectiveness of tinted lenses and tinted filters in these patients because of the weaknesses in methodology and statistics, variability in techniques in the trials, and the largely negative results.”

In April 2015, ophthalmologists in Maine stopped legislation to create a pilot program to screen for Irlen syndrome in elementary schools[3].

In April 2018, Royal Australian and New Zealand College of Ophthalmologists (RANZCO) released a position statement stating 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[4].


Currently, there is no strong evidence of a clear etiology of MISViS and the precise underlying mechanisms remain ill-defined. Some authors have proposed an autosomal hereditary component[5] or genetic marker in apolipoprotein B-100 (APOBM)[6]. However, more research is needed to confirm these studies.

Risk Factors

Possible risk factors for these visual symptoms reported in patients with MISViS and others include other learning deficits, traumatic brain injury (TBI), as well as headaches/migraines.


As stated above MISViS remains highly debated. The existing literature is unclear if MISViS exists separately as a distinct entity from dyslexia or other visual processing disorders. Several theories however have been proposed on the pathophysiology[7][8] but further research will be needed to confirm these findings.



Symptoms could include light-sensitivity, reading problems, discomfort, writing problems, depth perception, and visual distortions. Some studies suggest a possible association with other learning disabilities, such as attention deficit disorder (ADHD) and autism spectrum disorder (ASD)[9].

Clinical diagnosis

A proposed diagnosis of MISViS includes a review of the history, a formal self-survey to identify symptoms, a screen by “certified Irlen providers” and improvement of symptoms with addition of the colored lenses[10]. Unfortunately, there is no biomarker or imaging finding that can diagnose MISViS.

The self-survey screening and diagnosis process that has been described includes the following:  

  • Stage 1: initial screening with color overlays to reduce symptoms.
  • Stage 2: full assessment and determination of color combination for reduction of symptoms.

Training for diagnosing can be completed via training courses.

Differential diagnosis

The symptoms of the MISViS overlap significantly with other identifiable vision anomalies, such as accommodative, binocular, and ocular motor dysfunctions[11]. These other ocular motor conditions should be considered before establishing diagnosis, including dyslexia, ADHD, behavior problems, and psychological or psychiatric disorders.



MISViS reportedly responds to the use of colored (Irlen) lenses, as well as computerized accessibility options, like inverting colors and modifying background colors[5].

Studies on the use of these specialized lenses for MISViS have been variable and inconsistent and unfortunately much of the existing evidence base suffers from problems and limitations in methodology, data analytics, and variability in protocol in the available trials[12][13]. One systematic review of the available studies on MISViS showed high heterogeneity among studies, and lack of evidence on the existence of MISViS and treatment effectiveness.


Due to the debate about the efficacy of colored (Irlen) lenses for symptomatic patients with features of MISViS, the AAO recommends evaluation by an ophthalmologist with experience with pediatric care to exclude alternative etiologies. The discussion of MISViS should include a fair and objective discussion with the parents on the strengths and weaknesses of the available data and the status of the current recommendations. Other ocular motor pathology should be identified and treated if present.

It is unlikely that the controversy will be resolved without further study, but ophthalmologists should be aware of MISViS and be prepared to discuss the limitations of diagnosis and treatment on an individual basis with patients and their families.


  1. Chang L, Mruthyunjaya P, Rodriguez-Rosa RE, Freedman SF. Postoperative cilioretinal artery occlusion in Sturge Weber-associated glaucoma. J aapos. Aug 2010;14(4):358-60. doi:10.1016/j.jaapos.2010.04.014
  2. Joint Statement: Learning Disabilities, Dyslexia, and Vision - Reaffirmed 2014. 2014.
  3. American Academy of Ophthalmology (AAO). Ophthalmologists Derail Controversial Screening Proposal for Irlen Syndrome in Maine Schools. American Academy of Ophthalmology (AAO); April 30, 2015.
  4. Royal Australian and New Zealand College of Ophthalmologists (RANZCO). Irlen Syndrome. April 24, 2018.
  5. 5.0 5.1 Robinson GL, Foreman PJ. Scotopic sensitivity/Irlen syndrome and the use of coloured filters: a long-term placebo controlled and masked study of reading achievement and perception of ability. Percept Mot Skills. Aug 1999;89(1):83-113. doi:10.2466/pms.1999.89.1.83
  6. Loew SJ, Watson K. A prospective genetic marker of the visual-perception disorder Meares-Irlen syndrome. Percept Mot Skills. Jun 2012;114(3):870-82. doi:10.2466/
  7. Chouinard BD, Zhou CI, Hrybouski S, Kim ES, Cummine J. A Functional Neuroimaging Case Study of Meares–Irlen Syndrome/Visual Stress (MISViS).
  8. Evans BJ, Wilkins AJ, Brown J, et al. A preliminary investigation into the aetiology of Meares-Irlen syndrome. Ophthalmic Physiol Opt. Jul 1996;16(4):286-96. doi:10.1046/j.1475-1313.1996.95001190.x
  9. Giuliani F, Schwarz K. Connections between Autism Spectrum Disorders (ASD) and Meares-Meares-Irlen Syndrome. Autism-Open Access. 2017;07(04). doi:10.4172/2165-7890.1000216
  10. Kruk R, Sumbler K, Willows D. Visual processing characteristics of children with Meares-Irlen syndrome. Ophthalmic Physiol Opt. Jan 2008;28(1):35-46. doi:10.1111/j.1475-1313.2007.00532.x
  11. Evans B. The differential diagnosis of visual stress. presented at: Colour in the prevention of visual stress - latest research; 2021; Virtual.
  12. Patil J. Controversial treatment using coloured overlays in visual processing disorders. Indian J Ophthalmol. 2020:2327-2328. vol. 10.
  13. Alkhudairy Z, Al Shamlan F. The Use of Chromagen Lenses in Different Ocular and Non-ocular Conditions: A Prospective Cohort Study. Cureus. Sep 2022;14(9):e28963. doi:10.7759/cureus.28963
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