Could human tears be the key to diagnosing Parkinson's disease? Well, that's what some New Zealander researchers are trying to find out. Parkinson's disease affects more than 12,000 New Zealanders and is the fastest-growing chronic neurological disorder in the world. New Zealander researchers are leading a world-first study looking at tears and the role they might play in early diagnosis of Parkinson's. Dr Victor Dieriks Senior Research Fellow at University of Auckland and the lead researcher for this study.