Objectives: To identify causes of low vision among the patients in the Eye clinic of University of Nigeria Teaching Hospital (UNTH). Methods: This was a cross-sectional study of all new consecutive low vision patients seen at the eye clinic of University of Nigeria Teaching Hospital-(UNTH) Ituku-Ozalla. All patients with low vision were evaluated by the researcher and the findings entered on a research protocol. Data were analyzed using descriptive statistics to generate frequency and percentage distributions and analytical statistics to test for significance of observed inter-group differences. In all comparisons, statistical significance was indicated by p < 0.05. Results: A total of 197 patients were seen comprising of 120 males and 77 females (M:F = 1.6:1) aged 39.3 ± 22.9 SD years. The main causes of low vision in the study population were glaucoma (36.0%), followed by oculocutaneous albinism (14.7%). The mean presenting distant VA was logMAR 1.1 (95% CI), while the mean near VA is logMar 1.0 (6/60, 20/200). After refraction, the mean distant VA was logMar 1.0, using unpaired t-test, the difference between the distant presenting and refracted VA were not statistically significant. 57.9% had distant VA after optical low vision assessment of logMar 0.9 - logMar - 0.2 while the mean distant VA was logMar 0.8 which was statistically significant. Near vision after optical assessment improved with a mean of logMar 0.8, which was statistically significant. Conclusion: Glaucoma was the commonest cause of low vision in this study. Optical low vision aids improved the visual functions of majority of the patients in this study.