Perceptual Dyslexia
Definition…Perceptual Dyslexia is a visual-perceptual disorder affecting reading and writing based activities such as:
1.Reading 4. Math2.Writing 5. Copying3.Spelling 6. Reading music
• And other activities such as:1.Computer work 3. Sports performance2.Driving 4. Comfort under fluorescents
What Is Perceptual Dyslexia?
• Not standard dyslexia• Perceptual vice optical
– Based on sensitivity to light frequencies, not optical dysfunction
Victim can have 20/20 vision and still be affected
The way we see is not determined by what we want to see but how we have learned to practice seeing. There are several strategies that we pick between depending on what we have learned to see, and we switch between them as the task changes. So for example, a hunter uses a wide field of vision to locate prey,a scribe uses a narrow field to write and a painter or architectuses a variable field to arrange an ensemble into a whole. Eachdiscipline of seeing take practice. But suppose, like a dyslexic,you have a strategy inappropriate to reading.
When ordinary readers look at text…
The way we see is not determined by what we want to see but how we have learned to practice seeing. There are several strategies that we pick between depending on what we have learned to see, and we switch between them as the task changes. So for example, a hunter uses a wide field of vision to locate prey,a scribe uses a narrow field to write and a painter or architectuses a variable field to arrange an ensemble into a whole. Eachdiscipline of seeing take practice. But suppose, like a dyslexic,you have a strategy inappropriate to reading.
When dyslexics look at text…
Symptoms of Perceptual Dyslexia
• Light sensitivity• Problems with high-gloss or high-contrast
material• Inefficient reading• Slow reading rate• Attention deficit• Strain or fatigue• Poor depth perception
The Victims of Perceptual Dyslexia
• Estimated 46-50% of those with learning disabilities or reading problems
• Estimated 33% of those with dyslexia, ADD/HD, or other behavioral problems
• Estimated 12-14% of the general population
What They See
Blurry EffectR
eprin
ted
by p
erm
issi
on f
rom
Rea
ding
by
the
Col
ors
by H
elen
Irle
n
What They See
Halo EffectR
eprin
ted
by p
erm
issi
on f
rom
Rea
ding
by
the
Col
ors
by H
elen
Irle
n
What They See
Rivers EffectR
eprin
ted
by p
erm
issi
on f
rom
Rea
ding
by
the
Col
ors
by H
elen
Irle
n
What They See
Seasaw EffectR
eprin
ted
by p
erm
issi
on f
rom
Rea
ding
by
the
Col
ors
by H
elen
Irle
n
What They See
Shaky EffectR
eprin
ted
by p
erm
issi
on f
rom
Rea
ding
by
the
Col
ors
by H
elen
Irle
n
What They See
Swirl EffectR
eprin
ted
by p
erm
issi
on f
rom
Rea
ding
by
the
Col
ors
by H
elen
Irle
n
What They See
Washout EffectR
eprin
ted
by p
erm
issi
on f
rom
Rea
ding
by
the
Col
ors
by H
elen
Irle
n
What They See
Irlen Syndrome w/Dyslexia
Rep
rinte
d by
per
mis
sion
fro
m R
eadi
ng b
y th
e C
olor
s by
Hel
en I
rlen
What They See
Overlapping writing
Rep
rinte
d by
per
mis
sion
fro
m R
eadi
ng b
y th
e C
olor
s by
Hel
en I
rlen
Discovery by Irlen
Serendipitous discoveryA student using a red overlay noticed her page and words no longer swayed back and forth
Red did not work for everyone
Tried overlays of other colors– 31 out of 37 in class and 58 out of 75 in private practice
helped by colored overlays– Each individual helped had certain colors that made
things better or worse
Effects of Perceptual Dyslexia
• Brains of perceptual dyslexics are in “overdrive” when working problems
• Signal in visual neural pathways of optic nerves of perceptual dyslexics is different
Magnetic Resonance Imaging
• Dyslexics use different part of the brain for reading• Dyslexics use larger portion of brain’s capacity in
reading and visual tasks
Normal Brain Dyslexic Brain
Looking for the ReasonWhat Is the Cause ofPerceptual Dyslexia?
Receptor Field Theory :
– Developed in ’80s by visual physiologists
– Hypothesizes that cones of the eye organized into 8 sets of concentric, counterbalancing fields
Hypothesized Types of Receptor Fields
Receptor Field Theory
• Type of field determined by:– Field’s color region
arrangement– Balance of the
output of each field’s energy (signal)
» Positive or negative
Receptor Field Theory
• All receptor fields transmit their respective signal to brain’s visual processing center– Signals summed to
a unity, forming output image in brain
The way we see is not determined by what we want to see but how we have learned to practice seeing. There are several strategies that we pick between depending on what we have learned to see, and we switch between them as the task changes. So for example, a hunter uses a wide field of vision to locate prey,a scribe uses a narrow field to write and a painter or architectuses a variable field to arrange an ensemble into a whole. Eachdiscipline of seeing take practice. But suppose, like a dyslexic,you have a strategy inappropriate to reading.
The way we see is not determined by what we want to see but how we have learned to practice seeing. There are several strategies that we pick between depending on what we have learned to see, and we switch between them as the task changes. So for example, a hunter uses a wide field of vision to locate prey,a scribe uses a narrow field to write and a painter or architectuses a variable field to arrange an ensemble into a whole. Eachdiscipline of seeing take practice. But suppose, like a dyslexic,you have a strategy inappropriate to reading.
The way we see is not determined by what we want to see but how we have learned to practice seeing. There are several strategies that we pick between depending on what we have learned to see, and we switch between them as the task changes. So for example, a hunter uses a wide field of vision to locate prey,a scribe uses a narrow field to write and a painter or architectuses a variable field to arrange an ensemble into a whole. Eachdiscipline of seeing take practice. But suppose, like a dyslexic,you have a strategy inappropriate to reading.
The way we see is not determined by what we want to see but how we have learned to practice seeing. There are several strategies that we pick between depending on what we have learned to see, and we switch between them as the task changes. So for example, a hunter uses a wide field of vision to locate prey,a scribe uses a narrow field to write and a painter or architectuses a variable field to arrange an ensemble into a whole. Eachdiscipline of seeing take practice. But suppose, like a dyslexic,you have a strategy inappropriate to reading.
Reading with a window-mask
The way we see is not determined by what we want to see but how we have learned to practice seeing. There are several strategies that we pick between depending on what we have learned to see, and we switch between them as the task changes. So for example, a hunter uses a wide field of vision to locate prey,a scribe uses a narrow field to write and a painter or architectuses a variable field to arrange an ensemble into a whole. Eachdiscipline of seeing take practice. But suppose, like a dyslexic,you have a strategy inappropriate to reading.
The way we see is not determined by what we want to see but how we have learned to practice seeing. There are several strategies that we pick between depending on what we have learned to see, and we switch between them as the task changes. So for example, a hunter uses a wide field of vision to locate prey,a scribe uses a narrow field to write and a painter or architectuses a variable field to arrange an ensemble into a whole. Eachdiscipline of seeing take practice. But suppose, like a dyslexic,you have a strategy inappropriate to reading.
Reading with a window-mask
The way we see is not determined by what we want to see but how we have learned to practice seeing. There are several strategies that we pick between depending on what we have learned to see, and we switch between them as the task changes. So for example, a hunter uses a wide field of vision to locate prey,a scribe uses a narrow field to write and a painter or architectuses a variable field to arrange an ensemble into a whole. Eachdiscipline of seeing take practice. But suppose, like a dyslexic,you have a strategy inappropriate to reading.
The way we see is not determined by what we want to see but how we have learned to practice seeing. There are several strategies that we pick between depending on what we have learned to see, and we switch between them as the task changes. So for example, a hunter uses a wide field of vision to locate prey,a scribe uses a narrow field to write and a painter or architectuses a variable field to arrange an ensemble into a whole. Eachdiscipline of seeing take practice. But suppose, like a dyslexic,you have a strategy inappropriate to reading.
Reading with a window-mask
How To Fix It
• Dim the lights
• Use natural vice fluorescent lighting
• Use blackboards instead of white boards
• Allow students to use colored paper
• Allow caps/visors to be worn indoors
Cont…• Computers
– Can be modified using display options of operating system
» Brighten or dim background » Change background and font colors on
computer screen
• Modification of light spectrum presented– Colored film overlays– Colored eyeglass filters
• Each person’s color different
Testing for Color
• Irlen Method Two types of screening
-Quick, simple test, consisting of about 10-15 questions
-In-depth, reading-related screening (1½-2 hours)
Wilkins Rate of Reading Test:
–Fairly simple, easy to administer–Fairly quick “diagnosis” for
appropriate overlay(s)
More muted colours can improve visibility
The military services have traditionally been leaders in evaluating their personnel for physical and physiological attributes to place them in a workenvironment where their unique personal talents andcapabilities can be used. Using this screeningprocedure will provide a new avenue for selection formilitary personnel for placement in environments where their natural talents and abilities can be put to optimum use, while avoiding assignment of personnel to those operational environments where their visual performance parameters would cause them toinherently perform badly, thereby putting the mission, service assets, and/or other personnel at risk.
The military services have traditionally been leaders in evaluating their personnel for physical and physiological attributes to place them in a workenvironment where their unique personal talents andcapabilities can be used. Using this screeningprocedure will provide a new avenue for selection formilitary personnel for placement in environments where their natural talents and abilities can be put to optimum use, while avoiding assignment of personnel to those operational environments where their visual performance parameters would cause them toinherently perform badly, thereby putting the mission, service assets, and/or other personnel at risk.
The military services have traditionally been leaders in evaluating their personnel for physical and physiological attributes to place them in a workenvironment where their unique personal talents andcapabilities can be used. Using this screeningprocedure will provide a new avenue for selection formilitary personnel for placement in environments where their natural talents and abilities can be put to optimum use, while avoiding assignment of personnel to those operational environments where their visual performance parameters would cause them toinherently perform badly, thereby putting the mission, service assets, and/or other personnel at risk.
The military services have traditionally been leaders in evaluating their personnel for physical and physiological attributes to place them in a workenvironment where their unique personal talents andcapabilities can be used. Using this screeningprocedure will provide a new avenue for selection formilitary personnel for placement in environments where their natural talents and abilities can be put to optimum use, while avoiding assignment of personnel to those operational environments where their visual performance parameters would cause them toinherently perform badly, thereby putting the mission, service assets, and/or other personnel at risk.
The military services have traditionally been leaders in evaluating their personnel for physical and physiological attributes to place them in a workenvironment where their unique personal talents andcapabilities can be used. Using this screeningprocedure will provide a new avenue for selection formilitary personnel for placement in environments where their natural talents and abilities can be put to optimum use, while avoiding assignment of personnel to those operational environments where their visual performance parameters would cause them toinherently perform badly, thereby putting the mission, service assets, and/or other personnel at risk.
The military services have traditionally been leaders in evaluating their personnel for physical and physiological attributes to place them in a workenvironment where their unique personal talents andcapabilities can be used. Using this screeningprocedure will provide a new avenue for selection formilitary personnel for placement in environments where their natural talents and abilities can be put to optimum use, while avoiding assignment of personnel to those operational environments where their visual performance parameters would cause them toinherently perform badly, thereby putting the mission, service assets, and/or other personnel at risk.
The military services have traditionally been leaders in evaluating their personnel for physical and physiological attributes to place them in a workenvironment where their unique personal talents andcapabilities can be used. Using this screeningprocedure will provide a new avenue for selection formilitary personnel for placement in environments where their natural talents and abilities can be put to optimum use, while avoiding assignment of personnel to those operational environments where their visual performance parameters would cause them toinherently perform badly, thereby putting the mission, service assets, and/or other personnel at risk.
The military services have traditionally been leaders in evaluating their personnel for physical and physiological attributes to place them in a workenvironment where their unique personal talents andcapabilities can be used. Using this screeningprocedure will provide a new avenue for selection formilitary personnel for placement in environments where their natural talents and abilities can be put to optimum use, while avoiding assignment of personnel to those operational environments where their visual performance parameters would cause them toinherently perform badly, thereby putting the mission, service assets, and/or other personnel at risk.
The military services have traditionally been leaders in evaluating their personnel for physical and physiological attributes to place them in a workenvironment where their unique personal talents andcapabilities can be used. Using this screeningprocedure will provide a new avenue for selection formilitary personnel for placement in environments where their natural talents and abilities can be put to optimum use, while avoiding assignment of personnel to those operational environments where their visual performance parameters would cause them toinherently perform badly, thereby putting the mission, service assets, and/or other personnel at risk.
The military services have traditionally been leaders in evaluating their personnel for physical and physiological attributes to place them in a workenvironment where their unique personal talents andcapabilities can be used. Using this screeningprocedure will provide a new avenue for selection formilitary personnel for placement in environments where their natural talents and abilities can be put to optimum use, while avoiding assignment of personnel to those operational environments where their visual performance parameters would cause them toinherently perform badly, thereby putting the mission, service assets, and/or other personnel at risk.
Benefits
Improve individual quality of life Improved reading speed/comprehension Lower visual fatigue Longer attention span Reduced nervousness More self-confidence Improved attitude toward training Higher work-task efficiency
It's in our hands to change this sad situation and help the high
flights of ALL!