The new research adds to a body of work suggesting there is a link between eyesight and dementia.
A new study has pinpointed an early sign of dementia – suggesting that it could increase the likelihood of developing the disease.
As we get older, many of us dread losing our sight and our mental sharpness. However, fresh research indicates a potential link between visual problems and dementia. The study, conducted by researchers from the Kellogg Eye Centre at Michigan Medicine, part of the University of Michigan’s academic medical centre, was recently published in JAMA Ophthalmology.
It revealed that those with vision issues, including those who struggled to see clearly even with their prescription glasses or contact lenses, had a higher risk of dementia. The study involved over 3,000 elderly individuals who underwent vision and cognitive tests during home visits.
This latest research contributes to a growing body of evidence suggesting a connection between eyesight and dementia. The data is based on a nationally representative study of the elderly carried out in 2021 by the University of Michigan Institute for Social Research.
Participants in the study were all aged 71 or above, with an average age of 77. During the tests, a digital tablet was used to evaluate people’s near and distant vision, as well as their ability to discern letters that did not contrast sharply with their background.
Memory and reasoning tests were also conducted, with medical histories taken into account, including any previous diagnoses of Alzheimer’s or other forms of dementia. A third of those with moderate to severe distant vision impairment, including the blind, showed symptoms of dementia.
Similarly, 26 per cent of individuals who struggled to see letters that didn’t contrast well against a background also exhibited signs of dementia. Even among those with minor issues with distant vision, 19 per cent developed dementia.
Those with moderate to severe distant vision impairment were found to be 72 per cent more likely to have dementia than those without vision problems. Other types of visual impairment had smaller, yet significant, gaps, except for minor issues with distance vision, which showed no statistical difference.
People with various types of vision impairment were 35 per cent more likely to develop dementia than those without any sight issues. This study builds on previous research which found similar results, but relied on self-reported visual ability rather than objective testing, or it wasn’t representative of the US population.
The authors of the study stated: “Prioritising vision health may be key to optimising both sight and overall health and well-being. Randomised trials are warranted to determine whether optimising vision is a viable strategy to slow cognitive decline and reduce dementia risk.”
Sheila West, PhD of the Wilmer Eye Institute at Johns Hopkins Medicine, has highlighted a burgeoning body of proof tying vision to cognitive difficulties. Speaking about the impact of the new study’s findings, she said: “Equitable access to vision care services that prevent, reverse, or at least stave off progression of loss of sight is a worthy goal regardless of the potential impact on dementia and may be especially critical for those experiencing cognitive decline.”