The Prevalence of Colorblindness Among School Children in Akaki/Kality Sub-City Of Addis Ababa
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Date
2017-08
Authors
habte, Tsega
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa University
Abstract
In the human visual system, the eye receives physical stimuli in the form of
light and sends these stimuli as electrical signals to the brain, which interprets
them as images. The human eye has complex color perceptions, which are
initiated by cones in the retina and completed by impulse integration in the
brain. Most people see the world in color, but there are people who do not
perceive colors. These people may see colors differently than what most people
perceive. The inability of identifying colors is known as color blindness and its
prevalence varies between populations. The main aim of the present study was
to determine the prevalence of color blindness among children in Beseka and
Kality secondary schools. The study was conducted from March to May
2017.Random sampling method was used to estimate the sample size.
Accordingly, 1081 students from grade 9 and 10 of the two schools participated
in the study. Among these, 542 were females and 539 were males and their ages
range from 14 to 20 years. All the school age children in the selected schools
who have volunteered and a written consent from their parents or guardians
were included in the study. Color vision was tested by using Ishihara 24 plates
(Shinobu, 1972) and subjects were asked to seat in a room with sufficient light
and read the figures/symbols on the plates from a computer screen placed 75
cm away from the subject. The data were manually arranged and frequencies
were calculated. Among the 1081 students tested, 33(3.05%) have color vision
defect, and these included 9 (0.83%) females and 24(2.22%) males. It was
observed that the prevalence of color blindness is higher in males than in
females. It was recommended that schools and other teaching institutions
screen students for color vision deficiency, so that they can provide the
necessary assistance to such students.
Key words: Color Vision Deficiency, Ishihara’s Color plates, Protan, deutan, Tritan,
Ishihara colr plates
Description
Keywords
Color Vision Deficiency, Ishihara’s Color plates, Protan, deutan, Tritan, Ishihara colr plates