ABSTRACT.Purpose: An epidemiological study, concerning the prevalence of myopia among the student population (15-18 years old) of Northern Greece, was carried out. Methods: Specific questionnaires were used in order to collect data on the refractive condition of students. Results: Myopia prevalence was 36.8% and was found to be more common in females (46.0%) than in males (29.7%). The prevalence increased in students with myopic parents and myopic siblings. It was also found that myopia correlates strongly with nearwork and school performance. Conclusion:The study results suggest that myopia is a rather common refractive error in Greek students. Findings also indicate that myopia is probably hereditary and correlates with educational level, intelligence and excessive nearwork.Key words: myopia in students -epidemiology -heredity and myopia -nearwork -education. M yopia, as well as the other refractive errors, is a very common feature of the student population. According to extensive studies in various populations and in different countries, the distribution of myopia among students is variable. Several studies have shown that the prevalence of myopia increases with the level of education (Sperduto et al. 1983;Teasdale et al. 1988). It has also been supported that myopia is partly hereditary (Teikari et al. 1991;Zadnik et al. 1994). This study's aim is to examine the major epidemiological characteristics of myopia in the Greek student population and to identify the specific factors that cause myopia incidence. Material and MethodsIn 1998, there were about 220,000 students aged between 15 and 18 years attending High School in Greece. In order to collect the material, 12 high schools in four cities of Northern Greece (Thessaloniki, Larissa, Alexandroupoli and Nigrita) were chosen. These cities were selected as they represent the urban (Thessaloniki), the semi-urban (Larissa, Alexandroupoli) and the rural (Nigrita) population of Northern Greece. It is therefore assumed that the selected population represents a sufficient range of the socio-economic spectrum. A total number of 1852 questionnaires were distributed to students in order to collect data on their refractive condition. We consider the questionnaire method to be of sufficient validity, taking into account that certain other studies were based on this method (Teikari et al. 1991;Zadnik et al. 1994).Students were asked to quote their refractive situation using their ophthalmologist's prescription. They were also asked to determine their parents' and siblings' refractive situation, their performance at school, the hours they studied daily, the potential use of glasses or contact lenses and their habits. The questionnaires were anonymous and confidential.Students who complained of poor vision but had not had their visual acuity examined were excluded. On the other hand, we assumed that students with no visual acuity test and no subjective visual problems were emmetropes, and as such they were included in the study. Foreigners and immigrants of the last eight ye...

There is considerable variability in the prevalence of astigmatism worldwide, as indicated by different studies. However, this refractive error prevails at low levels in the Greek student population, compared with other countries.