AIM This study was designed to measure visual acuity and colour vision using conventional and simulated approaches; and compare both approaches with a view to recommending the use of the simulated - approach as a screening tool in Junior Secondary School students in Osogbo, Osun State, Nigeria. Materials and Methods This is a descriptive cross-sectional study conducted among students in public junior secondary schools in class one in Osogbo metropolis. Using multi-stage sampling technique, 496 students were recruited from 12 public junior secondary schools in three Local Government Areas (LGAs) of Osogbo metropolis. Visual acuity and colour vision were assessed by trained teachers and the researcher using the conventional Snellen and Ishihara charts as well as the simulated computerized method. Data collected were manually sorted out, and analyzed using IBM Statistical Package for Social Sciences (SPSS) version 22. The data were subjected to univariate and bivariate analyses. The level of significance for the study was set at p-value <0.05. Results The mean age of the respondents was 11.79, SD ±1.50 years. Males constituted 285 (57.5%) and females 211 (42.5%) of all respondents with a male to female ratio of 1.4:1. There was statistically significant level of agreement in the right eye (kappa = 0.773; p < 0.001) and left eye (kappa = 0.872; p < 0.001) between visual acuity readings using the conventional and simulated approaches. There was a statistically significant level of agreement in the right eye (kappa = 0.764; p < 0.001) and left eye (kappa = 0.957; p < 0.000) between colour vision readings using conventional and simulated approaches. Comparison of accuracy of the xix simulated approach in relation to the conventional approach (gold standard) to visual acuity screening showed a sensitivity of 98.5% with specificity of 90.9% for the right eye and a sensitivity of 99.1% with specificity of 97.2% for the left eye. Comparison the accuracy of the simulated approach in relation to the conventional approach (gold standard) to colour vision screening showed a sensitivity of 97.9% with specificity of 92.9% for the right eye and 99.4% sensitivity with 95.8% for the left eye.