Causes of visual impairment in children: a study of 3,210 cases.

Purpose: To determine causes of visual impairment in children at the Low Vision Service of the Ophthalmic Clinic at the University of São Paulo and at the Brazilian Association for the Visually Impaired People (Laramara), located in São Paulo, Brazil.

Patients And Methods: This study evaluated 3,210 visually impaired children (49% female, 51% male; average age, 5.9 years).