Sandra Stark, B. Optom, B.Sc. Hons. Stark-Griffin Dyslexia Academy, Johannesburg Area, South Africa

A Comparison of Dyop Color Perception and Dyslexia Diagnosis

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Acuity and accommodation

result from an array response of the L (red), M

(green), and S (blue) cone photoreceptors and

the relative refractive focal depths of those

specific colors. A Dyop® (or dynamic optotype)

is a spinning segmented ring visual target which

uses the strobic detection of the spinning gaps/

segments of the ring to measure visual function.

Dyop gap/segment color/contrast permutations

have distinctive, and corresponding, acuity

endpoints. This study’s objective was to compare

the qualitative acuity responses of a specific

Dyop color/contrast combination to diagnosed

symptoms of dyslexia.



One hundred and eighty-eight patients,

ranging in age from 4 years to 44 years, were

examined as patients of the Stark-Griffin Dyslexia

Academy to compare their relative color/contrast

acuity endpoint perception of a spinning green-on-

white Dyop versus a spinning blue-on-black Dyop

and the possible diagnosis of types of dyslexia.

The Stark-Griffin Dyslexia Academy trains eye care

professionals as to how to diagnose and treat

patients with potential symptoms of dyslexia. The

patients were diagnosed as to their prevalent type

of dyslexia, if any, through the Stark-Griffin Dyslexia

Assessment. The patients were then presented

with, as part of the Chart2020 vision test platform,

a display which has an identical-diameter spinning

green-on-white Dyop and spinning blue-on-black

Dyop with sufficient arc width diameter such that

both Dyop rings were detected as spinning. Those

identically sized Dyop rings were then reduced

in arc width until spinning of each of the colored

rings was not detected. The smallest diameter

ring where spinning was detected for each of the

color/contrast combinations (corresponding to

the acuity endpoint metric value) was recorded as

the color acuity endpoint.


This preliminary evaluation of the

disparity of color perception versus diagnosed

symptoms of dyslexia showed a strong positive

association (~86%) between color perception and

diagnosed symptoms of dyslexia. The findings

suggest that symptoms presented by dyslexics

could be better understood or analyzed by their

color perception.

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