In the Phase I, complex eye movements, including Fixation, Optokinetic Nystagmus (OKN), Guided Saccades, Microsaccades, Smooth Pursuit, and Pupillometry will be measured in 90 subjects (30 PD, 30 non-PD with other movement disorders (PSP, ET, CBD, etc.), and 30 normal defined as not having any symptoms of any neurological condition.) The patients will be classified according to clinical evaluations and clinical follow ups performed by Dr. Holly Shill, Director of the Lonnie and Muhammad Ali Parkinson Center at the Barrow Neurological Institute (Phoenix, AZ). A 3-way analysis will be performed to troubleshoot and optimize the detection and classification algorithms. At this stage, these results will only be used for the evaluation of the diagnostic capability of the tool and not to treat or diagnose the patient. The product is portable with the potential to be an accurate tool to diagnose PD. This tool will provide substantial support to neurologists by validating or complementing the clinical tests currently used to diagnose PD. Successful diagnosis of PD can open new avenues for diagnosing other neurological conditions.