الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 173 |  |  |
| | | from | 173 | | |
Abstract
Refractive errors is defined as a state in which the optical system of the non accommodating eye fails to bring parallel rays of light to focus on the fovea.
Myopia and hyperopia are the states of refractive error in which the optical system of the eye brings parallel rays of light into focus anterior and posterior to the retinal plane, respectively, resulting in blurred vision. Astigmatism is a state of refractive error of the eye in which the incident parallel rays can’t be focused to a single point.
According to the World Health Organization (WHO), uncorrected refractive errors such as myopia, hyperopia and astigmatism are the second leading cause of blindness after cataract and the main cause of low vision.
Visual impairment from uncorrected refractive errors can have immediate and long term consequences in children and adults, such as lost educational and employment opportunities, lost economic gain for individuals, families and societies, and impaired quality of life.
In children, refractive errors are the leading cause of amblyopia.
A cross-sectional descriptive study was carried out to study the prevalence of refractive errors in Delta region of Egypt among different age groups.
The population based study included 800 eyes of 400 patients attending the outpatient clinic of Banha Teaching Hospital from septamber 2016 to february 2017.
Patients were divided into two groups,a child age group )3-18 years)and an adult age group (19-59 years).
Our findings demonstrated that the preva¬lence of myopia was higher than the prevalence of hyperopia.
The prevalence of astigmatism was not only higher than myopia, but also greater than that reported in other studies.
The Prevalance of myopia was higher in the adult age group than in the child age group which was consistent with that of other East Asian countries.
The prevalance of hyperopia was higher in the child age group than in the adult age group.
The prevalance of astigmatism was slightly similar in both groups and was very high.