Lissencephaly is a rare disorder due to abnormal neural migration, causing neurological impairment and clinically characterised by mental retardation and epilepsy. Any disturbance of the visual pathway can cause loss of vision. The authors describe a case of a 6-year-old boy referred to the ophthalmologist presenting poor bilateral vision. This child had no other known medical conditions, and neurological examination was completely normal. Only when a magnetic resonance imaging was made that a lissencephaly-pachygyria with band heterotopia mostly occipital was noted. Cortical defects should be considered in order to diagnosis some visual defects in children.
Keywords: Binocular poor vision; cortical malformations; lissencephaly; visual defect.