Iren Research

Cornell University Case Studies Reveal Calm Brains With Irlen Spectral Filters

fMRI: Blank Lens (A) and with Precision Tinted spectral Filters (B)

Brain activity goes from overactive (A) to normalized (B) when wearing Irlen Spectral Filters.


Cornell University neuroscientists, Dr. Adam Anderson and Dr. Eve De Rosa, continue their ongoing investigations into Irlen Syndrome and Irlen Spectral Filters. Their recent case studies revealed a clear pattern of brain overact in individuals who suffer from Irlen Syndrome. The visual centers of the brain were particularly affected in these scans.


Irlen Syndrome (sometimes referred to in the literature as Meares-Irlen Syndrome, Scotopic Sensitivity Syndrome, or Visual Stress) is a problem with the brain, not the eye. It is a perceptual processing disorder, not a visual problem, a finding that the most current brain imaging research supports. In simplistic terms, when an individual suffers from Irlen Syndrome, their brain has difficulty or an inability to process certain wavelengths of light. In this way, light (especially bright and fluorescent lighting) becomes a stressor on the brain. This stress causes certain parts of the brain (e.g., the visual cortex) to become overactive. It is this over-activity and inability to effectively process visual stimuli that creates a variety of visual, physical, cognitive, emotional, and neurological symptoms.


There is currently a body of research related to Irlen Syndrome, Colored Overlays and Colored Filters that spans more than 30 years. The Irlen Method and the efficacy of colored overlays and colored lenses has been the subject of over 200 research studies encompassing the disciplines of education, psychology, and medicine. To date, more than 100 of these studies supporting the use of colored overlays and lenses to treat the perceptual processing difficulties associated with Irlen Syndrome are published in peer-reviewed academic and scientific journals, including the Journal of Learning Disabilities, Australian Journal of Special Education, Perceptual and Motor Skills, Australian Journal of Learning Disabilities, Journal of Clinical & Experimental Neuropsychology, Journal of Research in Reading, Behavioral Optometry, and Ophthalmological and Behavioral Optics, among others. A recent review of 62 studies published in peer-reviewed journals found 56 studies with positive findings, 45 with positive results for particular reading skills, and 11 showing improvements in accommodation facility, eye movements while reading, and reduced headaches/migraine. Independent research projects are ongoing at various universities in the United States, England, Australia, Switzerland, Brazil, and Italy. Research conducted over the last 15 years has addressed critiques about earlier methodology and offers empirically designed, placebo-controlled research resulting in positive results.


Notably, the most current research utilizes brain-mapping technology to show actual changes and normalization of brain functioning that is not achieved through ophthalmological treatments (plain lenses, prisms, or vision therapy). Researchers have utilized functional magnetic resonance imaging (fMRI), visual evoked responses (VER), and single photon emission computed tomography (SPECT) scans to objectively document the profound effects of visual sensory overload on the brain and the

normalization of brain activity when individually-prescribed, precision-tinted colored filters are worn. In one study by Amen and colleagues, comparing the brains of 42 people with Irlen syndrome to 200 age-matched individuals without any evidence of Irlen syndrome, SPECT showed increased activity in the brain’s emotional and visual processing centers and decreased activity in the cerebellum (an area that helps to integrate coordination and new information).


SPECT scans courtesy of the Amen Clinic
SPECT scans courtesy of the Amen Clinic


efficient brain imaging after irlen

Yellen and Schweller (2009) utilized state-of-the-art Visual Evoked Responses (VER), a portion of their comprehensive neuroelectrical evaluation of patients called the DESA®, and discovered that individuals with Irlen Syndrome have early hyper reactivity to visual stimuli somewhere between 30-60 milliseconds, and it is 3-9 standard deviations above normal (the Yellen-Schweller Effect). Irlen Spectral Filters reduce the standard deviation abnormalities of the Yellen-Schweller Effect, lessening of the delay of the brain coming back “online” and allowing it to clear sooner. Lewine et al. (1997) utilized magnetoencephalography (MEG) to characterize visual responses in conditions with and without lenses. In all cases, the evoked magnetic signal reflected a complicated pattern of bilateral activation of multiple cortical generators. A major difference in with and without lens conditions was seen between 170 and 200 msec post-stimulus. The data suggest that the coloured Irlen lenses provide for normalization and crystallization of visual information processing in individuals with Irlen Syndrome.

efficient brain cornell research 1
efficient brain cornell research 2

Chouinard et al. (2011) compared the neurological characteristics of a person with Irlen Syndrome with control subjects who were participating in a language. The descriptive results indicated that there are numerous significant differences in many areas of the brain cortex between the control subjects and the individual with Irlen Syndrome, providing evidence of a neurobiological foundation to Irlen Syndrome.

Huang et al. (2011) used fMRI to investigate differences between individuals suffering visual stress and controls in relation to migraine and to determine the effectiveness of precision-tinted colored filters for individuals suffering from visual stress. The research showed a normalization of cortical activation and spatial frequency tuning in the migraineurs by precision tinted filters that suggests a neurological basis for the therapeutic effect of these lenses in reducing visual cortical hyperactivation in migraine.

I encourage you to visit the research section of our website for a comprehensive list of references and summary of research related to Irlen and the use of color:

In addition, it is worth mentioning that Irlen Syndrome has been recognized by a number of organizations around the world. Colored overlays and/or colored filters are recognized as a standard accommodation for standardized testing in many states in America, including California, Arkansas, Florida, Oklahoma, Nevada, Massachusetts, New Mexico, and Washington. The SAT, LSAT, ACT, Recording for the Blind, Illinois Department of Rehabilitation, Indiana Office of Vocational Rehabilitation, Michigan Rehabilitation Services, Texas Commission for the Blind, Nevada Vocational

Rehabilitation Services, and Wisconsin Vocational Rehabilitation all officially recognize Irlen Syndrome. In Australia, the following are a sampling of agencies which have officially recognized Irlen Syndrome: Department of Employment, Education & Training, Departments of Army, Navy, and Air Force, Board of Studies – NSW, Board of Secondary Education – WA, Department of Children’s Services – WA, Commonwealth Employment Service (CES), Department of Rehabilitation, Geelong Medical Fund, and Technical and Further Education (TAFE).

From its discovery 35 years ago, Irlen has been the subject of scrutiny and criticism from a number of groups, particularly optometrists, who have sometimes suggested that the Irlen Method is not supported by scientific research and that the problems associated with Irlen Syndrome can be corrected through standard optometric interventions. Research has shown that binocular and accommodative anomalies may occur in conjunction with the syndrome, but are not considered to be the underlying physiological basis of the condition (Evans, Patel, Wilkins, Lightstone, Eperjesi,

Speedwell et al., 1999; Evans, Wilkins, Brown, Busby, Wignfield, Jeanes, &  Bald, 1996; Evans, Wilkins, Busby, & Jeanes, 1996; Scott, McWhinnie, Taylor, Stevenson, Irons, Lewis et al., 2002). Irlen has also been reviewed by various USA Boards of Optometry and the USA Medical Board and was found not to be either the practice of optometry or medicine. As a perceptual problem, it is similar to other processing problems (both visual and auditory) that are diagnosed by psycho-educational testing and treated within the educational system.

There are more than 100 scientific research studies on the topic of Irlen Syndrome that are published in peer-reviewed scientific journals. These studies have most often been conducted by independent researchers with no financial investment in the method. This research has established a hereditary component of the disorder (Loew &  Watson, 2012; Robinson, Foreman, &  Dear, 2000; Robinson, Foreman, Dear &  Sparkes, 2004), a number of biochemical markers for problems associated with Irlen Syndrome (Robinson, Roberts, McGregor, Dunstan, &  Butt, 1999; Robinson, McGregor, Roberts, Dunstan &  Butt, 2001; Sparkes, Robinson, Dunstan, &  Roberts, 2003), and differences between both the anatomy and functioning of brains of individuals with Irlen Syndrome

(Chouinard, Zhou, Hrybousky, Kim, &  Commine, 2012; Huang, Zong, Wilkins, Jenkins, Bozoki, &  Cao, 2011; Lewine, Davis, Provencal, Edgar, &  Orrison, 1997; Riddell, Wilkins, &  Hainline, 2006; Yellen & Schweller, 2009). The research has repeatedly documented efficacy of both colored overlays and spectral filters, as measured by improvements in a variety of reading skills (Bouldoukian, Wilkins, & Evans, 2002; Nobel, Orton, Irlen &  Robinson, 2004; Park, Kim, Cho, Joo, 2012; Robinson &  Foreman,

1999; Tyrrell, Holland, Dennis, & Wilkins, 1995; Williams, LeCluyse, & Rock Faucheux, 1992; Wilkins, Evans, Brown, Busby, Wingfield, Jeanes & Bald, 1994), reduction in physical symptoms that include headaches, migraines, eye strain, fatigue, and light sensitivity (Barbolini, Lazzerini, Pini, Steiner, DelCecchio, Migaldi, & Cavallini, 2009; Bulmer, 1994; Chronicle & Wilkins, 1991; Huang et al., 2011; Wilkins & Wilkinson, 1991), and improved functioning and success in both academia and the workplace (Bulmer, 1994; Irlen & Robinson, 1996; Robinson & Conway, 1994; Robinson & Conway, 2000; Whiting & Robinson, 1988; Whiting, Robinson, & Parrot, 1994). Most recently, a study conducted in Korea confirmed the improvements in reading with precision-tinted colored filters by utilizing fMRI data to quantify corresponding self-report data (Kim et al., 2015).

What To Know More About The Ongoing Irlen Research?


  • rgb_logo_efficient brain favicon 300x300

    Dr. Jeri LaVigne


6284 Hunting Creek Rd NE

Atlanta, GA 30328


Privacy Policy