The results from longitudinal follow-up of the incidence of refractive eye errors in a population from rural region have contributed to the characteristics of the regional gene pool. Generation born within 1950-1964 (Generation I.) was compared with that bornwithin 1980-1994 (Generation II.). At the same time, a long-term follow-up has demonstrated changes in the quantity of phenotypes in absolute number (values of morbidity: generation I. - all types of refractive errors: urban population men 104/1000, women 132/1000. Rural population men 119/1000, women 135/1000. Generation II.: urban men 132/1000, women 169/1000, rural men 124/1000, women 136/1000. The difference in morbidity between women and men in the Ist and IInd generations, both urban and rural, has not changed. A more pronounced difference can be seen in urban population, namely atmyopia in both generations (myopia urban population: generation I. men 40.8 %, women 59.2 %, generation II. men 43.9 %, women 56.1 %, myopia rural population: generation I.: men 44.2 %, women 55.8 %, generation II.: men 47.2 %, women 52.8 %. Hyperopia urban population: generation I., men 46.7 %, women 53.3 %, generation II. men 47.3 %, women 52.7 %. The incidence of astigmatism has shown constant ratio 1:1 both between men and women, and urban and rural populations. These changes were demonstrated most markedly in urban population, but these deviations are caused by emigration from rural to urban districts, especially from a hinterland. 10 % of IInd generation (1980-1994) are relatives of Ist generation (1950-1964) only.

        Key words: refractive errors,myopia, hyperopia, astigmatism, fenotype, genotype, urban population, west Moravia, selection