Work, led by Lancaster University in partnership with Royal Preston Hospital, Lancashire Teaching Hospitals NHS Foundation Trust, has shown that people with Alzheimer's disease have difficulty with one particular type of eye tracking test. As part of the study, 18 patients with Alzheimer's disease, 25 patients with Parkinson's disease, 17 healthy young people and 18 healthy older people were asked to follow the movements of light on a computer monitor, but in some instances they were asked to look the opposite way, away from the light.To see more details visit, medicalxpress.com