This study will include one visit:
* Written consent will be obtained from all participants
* Inclusion and exclusion criteria will be checked
* An ophthalmologic test, a pregnancy test, a alcohol test and a salivary test will be realized
* Various symptoms will be assessed with the PANSS (Positive And Negative Syndrome Scale for schizophrenia) and the UPDRS (Unified Parkinson Disease Rating Scale for patients, the MOCA (Montreal Cognitive Assessment), The HAD (Hospital Anxiety and Depression Scale) and the MINI (Mini International Neuropsychiatric Interview) for all participants.
* The task will be divided in two parts:
A visuo-spatial task allowing to record saccadic eye movements (approximately 10 min).
The change blindness session lasted approximately 20 min.
