The Use of Tinted Lenses and COLORED OVERLAYS for the Treatment
of Dyslexia and Other Related Reading and Learning Disorders
Over the past two decades the use of tinted lenses and COLORED
OVERLAYS to improve reading comfort and performance has been
presented in both the popular media and professional literature.
With increasing frequency, patients and parents consult
optometrists about the value of COLORED OVERLAYS and tinted
lenses. Meares1 and
later Irlen2 described
a syndrome of visual symptoms and distortion that can be
alleviated with colored filters. This syndrome has been referred
to as "scotopic sensitivity syndrome" or the Irlen Syndrome.3 COLORED
OVERLAYS and tinted lenses are purported to improve reading
ability and visual perception, increase sustained reading time,
and eliminate symptoms associated with reading such as light
sensitivity, eyestrain, headaches, blurring of print, loss of
place, and watery eyes.
A comprehensive review of the available scientific literature
regarding the effectiveness of tinted lenses or filters revealed
There is evidence that the underlying symptoms associated with
the Irlen Syndrome are related to identifiable vision anomalies,
e.g., accommodative, binocular, and ocular motor dysfunctions,
in many patients seeking help from colored lenses.4-7 Furthermore,
such conditions return to normal function when appropriately
treated with lenses, prisms, or vision therapy. When patients
exhibiting the Irlen Syndrome were treated with vision therapy,
their symptoms were relieved. These patients were no longer
classified as exhibiting this syndrome, and therefore did not
demonstrate a need for the COLORED OVERLAYS or tinted lenses.4
Most investigators have not controlled for the presence of
vision anomalies, e.g., accommodative, binocular, and ocular
motor dysfunctions. In most cases, researchers have simply
assumed that a history of a previous eye examination ruled out
any significant vision problem.8-14 Others
have developed a protocol to screen for vision problems but have
not included an adequate battery of tests to eliminate common
accommodative, binocular, and ocular motor dysfunctions.3,
The results of prospective, controlled research on the
effectiveness of tinted lenses or COLORED OVERLAYS vary. One
randomized, controlled trial demonstrated that children with
reading difficulties, who were prescribed filters based on
COLORED OVERLAYS, experienced reduced symptoms of asthenopia.15
While this study suggests the color may need to be individually
and precisely prescribed, another study demonstrated
significantly improved eye movements among reading disabled
children when reading through blue filters.20 Other
researchers failed to find improvement in comprehension scores
in readers using tinted lenses.4
Results of testing utilized to determine the most appropriate
color are not repeatable.21, 22 There
are numerous variables within the individual and the environment
(such as differences in lighting between the home and various
classrooms) that can influence the effectiveness of assigned
overlays. It has been reported that up to twenty-five percent of
the time, children who receive tinted lenses need to have their
tints adjusted within the first year.23
The effect of spectral filters and COLORED OVERLAYS is not
solely a placebo.15 COLORED
OVERLAYS and tinted lenses are not cures for dyslexia, but may
be useful reading aids for some individuals with reading
The underlying physiological mechanism for the Irlen Syndrome is
still not known. While some argue that a magnocellular deficit
exists in these individuals,25-29 others
suggest the problem is pattern glare.30, 31
There is lack of agreement about the best way to evaluate
patients for the presence of the Irlen Syndrome. Some suggest
the use of the Irlen 2-part evaluation system,32 while
others promote the use of the Intuitive Colorimeter.33 Both
systems require additional research.
Visual processing is a fundamental part of the reading process.34 Future
research must address the issue of underlying vision anomalies,
sub‑typing of reading disabilities and the differential response
to different treatments. Controlled clinical research will allow
reading and learning disabled individuals, their parents, and
the professionals who work with them, to better evaluate the
effectiveness of available treatments for each individual.
Therefore, it is the position of the American Optometric
Undetected vision problems may be a factor in individuals
who exhibit the symptoms of the Irlen Syndrome. A
comprehensive eye/vision examination with particular
emphasis on accommodation, binocular vision, and ocular
motor function is recommended for all individuals
experiencing reading or learning difficulties, as well as
those showing signs and symptoms of visual efficiency
The American Optometric Association encourages further
research to investigate the effect that specifically tinted
lenses and COLORED OVERLAYS have on visual function related
to reading performance.
Vision problems are a frequent factor in reading
difficulities. Ignoring the role of vision or inadequately
evaluating the vision of individuals with reading problems
is a disservice which may prevent the person from receiving
This publication was formulated by the American Optometric
Association’s Binocular Vision Working Group. The following
individuals are acknowledged for their contributions:
Gary J. Williams, O.D., Chair
Gregory Kitchener, O.D.
Leonard J. Press, O.D.
Mitchell M. Scheiman, O.D.
Glen T. Steele, O.D.
Approved by: American Optometric Association, April 2004
Meares O. Figure/ground, brightness contrast, and reading
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Irlen H. Successful treatment of learning difficulties. in
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Evans BJ, et al., A preliminary investigation into the
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Blaskey P, et al. The effectiveness of Irlen filters for
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Scheiman M., et al., Vision characteristics of individuals
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Lopez R. et al. Comparison of Irlen scotopic sensitivity
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Hoyt CS. Irlen lenses and reading difficulties. J Learning
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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
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Robinson GL, Miles J. The use of overlays to improve visual
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Robinson GL, Conway RNF. Irlen lenses and adults: a
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Whiting PR. Improvement in reading and other skills using
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Solan HA, et al.. Eye movement efficiency in normal and
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Solan HA, et al., Transient and sustained processing:
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Solan HA, et al., Coherent motion threshold measurements for
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Lehmkuhle S, et al. A defective visual pathway in children
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