July 14, 2023 – People who have vision problems but don’t wear glasses or seek treatment, such as surgery, are more likely to have dementia, according to the most comprehensive study on the topic in 15 years.
The findings suggest that “optimizing” vision, such as wearing glasses or getting cataract surgery, could help prevent dementia. The authors wrote that further study is needed to evaluate how vision optimization impacts cognitive decline and dementia risk.
The results were published Thursday in the journal JAMA Ophthalmology and included data from 2,967 people age 71 years and older who took tablet-based vision tests as part of the 2021 National Health and Aging Trends Study. They also answered survey questions about cognition and dementia. The vision tests measured how well people could see things that were far away, things that were very close to them, or things that didn’t have a clear outline to distinguish them from the background.
Overall, 12% of study participants had dementia. Their average age was 77 years old.
However, when researchers looked at people with uncorrected vision problems, they found that:
- 22% of people who had trouble seeing things near to them had dementia
- 33% of people who had moderate or worse trouble seeing things far away had dementia
- 26% of people with contrast sensitivity had dementia
People who had multiple vision problems had an even higher likelihood of having dementia.
Researchers said their findings are the first major update to data on the link between vision and dementia in 15 years, and that older data used self-reported vision function information, which likely meant it wasn’t accurate.
In a commentary published alongside the study, Johns Hopkins Medicine ophthalmology professor Sheila West, PhD, Pharm D, wrote that the study points to a need to further explore the link between vision problems and dementia because it may not simply be a matter of physical changes in the brain.
“Visual loss is associated with social isolation, difficulty reading, and in general a decrease in personal and social stimulation,” West wrote. “Personal and social isolation are risk factors for cognitive decline. If there is even an indirect link between vision impairment and loss of cognition, then improving vision should decrease the risk of dementia or at least slow progression.”
West noted that providing vision care to people in dementia care settings is difficult because, for example, eyeglasses are often lost, or families may not believe surgery is worth the emotional trauma.
The CDC says more than 5 million people in the U.S. have dementia, and that number is expected to increase to 14 million by 2060.
