·AIM: To assess the incidence of refractive error among adult population: a Hospital base study.·METHODS: This Hospital based study was conducted between June 2008 to November 2008 at tertiary referral center, Liaquat University Eye Hospital, Hyderabad. All subjects underwent a complete ophthalmic examination. The best corrected visual acuity(BCVA) was ecorded. Refraction data are based on subjective refraction. Only the right eye of each subject was considered. Hypermetropia was defined as a spherical equivalent greater than +0.5 diopter sphere (DS). Emmetropia was defined as a spherical equivalent between -0.50 and +0.50DS, myopia was defined as a spherical equivalent worse than -0.50DS and a spherical equivalent or worse than -5.00 DS was classified as a high myopia. Astigmatism correction was prescribed in minus cylinder format, and astigmatism was defined as cylinder error worse than -0.50 diopter cylinder (DC) in any axis. ·RESULTS: Eight thousand and four hundred patients were attended the out patients department with age range of 20-60 years. The proportion of men and women was 61∶ 39. Both the rural and urban population were treated. Sixty seven percents of patients has completed their higher secondary education.Of the total 8 400 patients 2 719(32 37%) had BCVA 20/40 or better and remaining 5 681(67.63%) had BCVA poor than 20/40 due to different anterior and posterior segment eye pathologies, and were excluded from study. Of the 2 719 patients 1 065(39.17%) were phakic in right eye and making the 12.68% of total (8 400) examined patients, and remaining 1 654(60.83%) were pseudophakic. The result were analyzed for only 12 68(1 065 phakic ametropic patients) percent of total treated patients in last 6 months. There were 590(55.40% of phakic patients) men and 475(44. 60%) women.Hypermetropia was found in 300 patients (28.20% of phakic ametropic). Six hundred and ninety (64.80% of phakic ametropic) patients had myopia. The incidence of myopia increased significantly with age. High myopes constituted 7%(75) of the study population. Four hundred and five (38.03% of phakic) patients had astigmatism worse than 0.5D cylinder. There were 195(48.15%) men and 210(51.85%) women. ·CONCLUSION: Refractive error is a significant public health problem in our population that may be impact on visual function and activities of daily life. Optimal visual function may be compromised with uncorrected or under-corrected refractive errors.