["Bell clappers" with "ophthalmologic alarm". Apropos of 2 cases of colloid cysts of the 3d ventricle].

: We report two cases of third ventricle colloid cyst in atypical adult's neurological descriptions, tracked down by ophthalmologist, proved by computed tomography and magnetic resonance imaging. We describe physio-pathological mechanism and dwell on different ophthalmological events of exceptional occurrence with those benign tumours and on ophthalmological investigation's importance in case of persisting and unexplained headache. We conclude with spontaneous clinical course, and neurological surgery's efficacy on hydrocephalus.