The aim of the present study is to gain more information about retinal functional parameters in myopic children in Europe. For this purpose, a prospective case-control study in children aged between 8 and 13 years, as this is the usual age of myopia onset, will be conducted. Forty myopic children will be age- and sex-matched to non-myopic controls. Retinal oxygen extraction will be used as the main outcome parameter, as data from animal and human studies point towards an involvement of hypoxia in the disease process. In addition, other parameters probably linked to myopia will be investigated, such as retinal and choroidal blood flow as well as choroidal and retinal vessel density and anatomical structures such as choroidal and central retinal thickness. Also, questionnaires about lifestyle factors will be completed.