Alzheimer's disease (AD) is often mis-perceived as a disorder largely or solely of memory. However the disease also affects the visual areas of the brain leading to problems seeing what and where things are. Dementia-related visual impairment tends to be neglected, partly because people assume any problems are due to the eyes rather than the brain, and because it occurs at a point when language and other skills are too impaired for the person with dementia to explain the perceptual problems they are having. Visual problems are also often mis-attributed to poor memory (eg a person with AD failing to recognise a family member in a photo may be thought to have 'forgotten' the person, when in fact they may simply be unable to perceive the face clearly). Visual impairment in AD has received increased attention recently with the identification of the syndrome Posterior Cortical Atrophy (PCA) which is typically caused by AD but presents with dramatic impairment of vision not memory, as experienced and described by the author Terry Pratchett in his documentary Living with Alzheimer's.

The project objective is to demonstrate that helping AD patients to interact more successfully with their visual environment at home can have a significant positive impact upon the wellbeing and quality of life of both patients and carers. The project will involve 50 people with PCA, 150 with typical Alzheimer's disease and 100 healthy volunteers. The impact of visual aids and strategies will be measured at three time-points over the course of one year, with a staggered start to enable comparisons of quality of life in those with and without the intervention. The success of the project will be judged primarily using established measures of quality of life, caregiver burden, everyday abilities, and behavioural and psychological wellbeing. However, the design of the visual aids and compensatory strategies themselves will be based upon a combination of patient/carer interviews (qualitative evidence) and cutting-edge scientific understanding of the nature of visual impairments caused by conditions such as Alzheimer's disease (quantitative evidence). This quantitative evidence will be gathered through studies of patient's visual skills and eye movements, and their ability to move around a purpose-built laboratory environment, before the main study commences in patients' own homes.