Background: Low vision and blindness are significant public health issues worldwide. They result in educational, occupational, and social challenges in the affected persons. Their care givers/ families are also severely affected. There is however limited data on the magnitude of visual impairment in Aba, South East Nigeria. Objective: To determine the prevalence and causes of low vision and blindness among adult patients attending eye clinic in a tertiary hospital in South East Nigeria. Materials and Methods: This was an institutional-based retrospective, descriptive study involving 457 patients who attended Abia State University Teaching Hospital eye clinic between April and September 2018. Data was obtained from patient’s hospital records within the period under study and analyzed using IBM SPSS version 25.0. Statistical significance was set at a P-value of < 0.05. Results: Data of 457 ophthalmic patients who met the inclusion criteria for this study were analyzed. Mean age of respondents was 48.5 ± 17.7 years. A total 5.4% of the patients had bilateral low vision, while 30.2% and 7% had monocular and bilateral blindness respectively. Cataract-related diagnosis, refractive errors and glaucoma (28.4%, 28.2% and 14.7%) respectively were the major causes of low vision and blindness among the patients. Statistically significant association was found between respondent’s diagnosis and age as well as occupation (P<0.001). Conclusion: Results from this study will aid in planning low vision & blindness preventive programs and improving eye care services.