Introduction:. Higher-order aberrations (HOAs) are small optical irregularities or imperfections of the eye which cannot be corrected by simple sphere and cylinder corrections. Many authors believe that HOAs are the reason many patients complain of halo, glare and decreased contrast sensitivity after successful corneal refractive surgery.(Baily et al., 2003)
Many studies in the past showed significant variability of HOAs among the individuals of same population. Popularization of laser corneal refractive surgery and its potential to induce or remove optical aberrations (both low order and higher order aberrations) is the main reason behind better understanding of the nature of aberrations as well as their influence on visual quality. (Bisneto et al., 2007)
Aim of the work:To measure and evaluate the distribution of HOAs among various refractive errors in individuals screened for refractive surgery and compare them .correlation with errors.
Patients and Methods: prospective  cross sectional analytical study was conducted at ophathalmology center for refactive surgery ,sohag started  in February  2016. two hundred eyes of patients with age ranging from 18-40 years were included in the study.
Results: Patients in hypermetropia group had statistically significant higher amount of HOA than other three groups followed by mixed group.No significant correlation of HOAs with amount of refractive error in all the groups except in mixed error group.
Conclusion: In overall comparison we noticed the mean RMS of total HOAs  were significantly higher in hypermetropia group  and there was a statistically significant correlation between SE of  Mixed group and RMS of Total HOAs.