Inclusion Criteria:  age ≥18 years, myopic sphere of -6 diopters or more, astigmatism less than 3 diopters, stable myopia not progressing for more than one year  Exclusion Criteria:  age <18 years, myopic sphere less than -6 diopters, astigmatism greater than 3 diopters, progressive myopia (variation of more than 0.5 diopters over one year), abnormal corneal topography or the presence of manifest keratoconus, pre-existing eye pathology, history of eye surgery, active inflammatory or infectious eye disease, dermatological disease or systemic connectivitis