Prevalence of refractive errors in students with and without color vision deficiency

Purpose: to evaluate refractive errors in school age children with color vision deficiency (cvd) and those with normal color vision (ncv) in order to make a better understanding of the emmetropization process. methods: a total of 4,400 primary school students aged 7-12 years were screened for color vision using ishihara pseudoisochromatic color vision plate sets. of these,160 (3.6%) students had cvd. a total of 400 age- and sex-matched students with ncv were selected as controls. refractive status was evaluated using objective cyclorefraction. results: the cvd group included 136 male (85%) and 24 female (15%) subjects with mean age of 10.1 ± 1.8 years. the ncv group comprised of 336 male (84%) and 64 female (16%) subjects with mean age of 10.5 ± 1.2 years. the prevalence of myopia (7.7% vs. 13.9%,p < 0.001) and hyperopia (41% vs. 57.4%,p = 0.03) was significantly lower in the cvd group. furthermore,subjects with cvd subjects demonstrated a lower magnitude of refractive errors as compared to the cvd group (mean refractive error: +0.54 ± 0.19 d versus + 0.74 ± 1.12 d,p < 0.001). conclusion: although the lower prevalence of myopia in subjects with cvd group supports the role of longitudinal chromatic aberration in the development of refractive errors; the lower prevalence of hyperopia in this group is an opposing finding. myopia is a multifactorial disorder and longitudinal chromatic aberration is not the only factor influencing the emmetropization process.