Abstract

Background: Color vision refers to our ability to perceive colors based on spectral variations in light absorbed by the photoreceptors. Color blindness or color vision deficiency is the inability or decreased ability to perceive color differences under normal lighting condition. This is predominantly caused by inherited photo pigment abnormalities in the retina resulting in a smaller number of visible spectral hues in both eyes. Red green color vision defects are common and caused by rearrangement and deletions of genes on the X-chromosome. Color blind persons, unaware of their disability, may choose certain professions, which may not be suitable for them, like traffic policeman, train driver or technician in color industries, which require proper color perception leading to lesser efficiency in work as well as may cause accidents. Objectives: This study was conducted to find out the prevalence of color blindness among secondary school students in Butajira town, Gurage zone Ethiopia. Methods: A cross sectional descriptive study was conducted from February 18, 2019 to March 8, 2019. A total of 779 (399 male & 380 female) students with age range of 14-25 years were selected using multistage sampling technique from three secondary schools. Participants were screened for color vision deficiency by using Ishihara’s tests for color vision deficiency. Results: Among the 779 students screened for color vision deficiency, 13 of them (1.7%) were diagnosed with color blindness out of which 12 were male and 1 was female. Deuteranomally was the most frequent color vision defect detected (11, 84.6%) and protanopia was the least detected color vision deficiency with 2 cases (15.4%). All participants with color vision deficiency were not aware of their color vision status. Conclusion: Screening for color vision deficiency is potentially useful for adolescents in making carrier decisions. In our study participants were not aware of their color vision status or not informed about color vision deficiency and its impact in day to day life or future carrier performance. Therefore, we recommend early screening of children in order to help evaluate its effect in school activities and adolescence at time of entry to college in departments which require good color perception, training teachers on color vision deficiency screening to understand and help improve students’ performance in school activities, creating awareness among the society about CVD and its effects in day to day and professional life and since prevalence of CVD varies in different ethnic groups further studies in other parts of the country may help to identify areas to focus on in the future.