At each site, corneal tomography examinations (Pentacam) will be performed bilaterally in children and adolescents, who are not ill or with any ophthalmological symptom. The population to be studied will be composed of children and adolescents on medical visits for non-ophthalmologic reasons, aged between 6 and 20 years. Multiple cities, from different continents (North America, South America, Asia and Europe) will participate.