purpose: to evaluate the preschool vision screening program coverage and to assess its validity indices including specificity, negative predictive value (npv), sensitivity and positive predictive value (ppv) and the frequency of treatment for visual impairment. methods: a sample of 906 six-year-old children signed up for primary school registration in the shahrood district (semnan, iran) were r...

Introduction: It is important to recognize the extent which views on persons with visual impairment have changed over years. From looking at this issue as a medical condition, it nowadays being regarded human rights has today been embedded into legally binding instruments national, regional and international levels. Purpose: The purpose of work address aspect impairment, challenges faced assess...