The number of people with dementia is increasing. In 2019, dementia affected 57.4 million people worldwide, and this number is expected to almost triple to 130 million by 2050 (Global Burden of Disease Study Dementia Forecasting Collaborators, 2022).

Combined, the impact of dementia and visual impairment (VI) – which is also rising as global populations age – can be devastating. People living with both dementia and sight loss are likely to experience more disorientation and greater mobility problems and have an increased risk of falls. They may also have problems with communication, understanding and learning new tasks, loss of activities and increased social isolation (Alzheimer’s Society, 2022). Sight loss affects an estimated 250,000 people with dementia in the UK (RNIB, 2018), but so far the association between VI and dementia has been poorly understood. 

However, a new study has found a link between the severity of VI and the risk of dementia. Zhu et al (2021) examined data from 117,187 British adults aged 40 to 69 deemed free of dementia at baseline who were taking part in the Biobank Study (a biomedical database containing anonymised genetic, lifestyle and health information from 500,000 participants).