Simulated eye test for Alzheimer's disease. Normal eye with pupil contracted before the application of tropicamide eye drops. The eye drops will widen (dilate) the pupil, as seen in photo M108/328. This pupil reaction is being tested as a tool to diagnose patients with Alzheimer's disease. The eyes of Alzheimer patients are highly sensitive and react (dilate) to tropicamide eye drops at low concentration, to which healthy eyes do not respond. Alzheimer's disease is usually only confirmed after postmortem. An eye test would lead to early treatment of Alzheimer's disease. Tropic- amide is widely used in normal eye tests.