Background & Objectives: Visual impairment included mild visual loss to total blindness that depends on the definitions different results achieved in various studies in all over the world. These kinds of studies will be helpful for social and health problems because some of the causes of blindness are preventable and curable at early stages.

  Methods: This study is a cross-sectional study. In this study, 300 patients older than 40 years with CF visual acuity or less had been surveyed, and information related to the patients recorded in questionnaires. The patients diagnosed by expert physician and recorded data were analyzedby descriptive statistical methods.

  Results: 57% of patients were male and 43% were female, and 41% were urban and 59% rural. The most common cause of visual impairment regarding to the definitions in this study was cataract (57%) and primary glaucoma (16%), uveitis (61%), corneal disease (6%), ARMD (4.33%), diabetic retinopathy (4%) and refraction disorder (myopia) were respectively after cataract and central retinal artery obstruction with 0.66% had the less prevalence. At all, retinal disease with 15% of prevalence was in third place of the major causes of visual impairment. Cataract was the cause of 43.9% of visual impairment in men and 74.4% in women. Glaucoma (24.6%) was the second cause in men and third common cause of visual impairment in women with 4.7% and comparing with men has lower prevalence.

  Conclussion: In this study cataract and glaucoma were the main causes of visual impairment, same as global studies, respectively. In this study prevalence of glaucoma in men was more than the prevalence in women and appears to be related to the fact that women are more sensitive to their health status comparing with men and they go to ophthalmologists sooner than men. With knowing that glaucoma will be controllable with appropriate treatments at the early stage and irreversible visual loss will be prevented.