Our eyes, it’s often said, offer a glimpse into our brain. Recent research indicates they might even provide early indicators of cognitive decline.
Two large population studies—one from the UK and the other from Australia—suggest that individuals scoring lower on basic vision tests may face a higher likelihood of developing dementia many years down the line.
The UK research, published in 2024, found that slower visual processing speeds correlated with a greater risk of dementia over the next twelve years.
Similarly, the Australian study identified that a decline in visual acuity was a crucial predictor of cognitive deterioration over a comparable time frame.
“Vision decline can stem from various treatable conditions, such as cataracts or refractive errors that can be corrected with glasses,” noted the head researcher from the Australian study, neuroscientist Nikki-Anne Wilson at Neuroscience Research Australia (NeuRA).
“What these studies are showing is that recognizing and addressing these vision changes early could potentially lower the risk of developing dementia.”
In light of this compelling evidence, The Lancet‘s recent Commission on dementia in 2024 pointed out that vision loss later in life is a new risk factor, accounting for up to 2.2 percent of dementia cases.
In contrast, untreated hearing loss during mid-life is linked to an estimated seven percent of cases.
However, not every older person who experiences hearing or vision loss is doomed to develop dementia. These issues might point to various underlying health problems, making sensory tests unreliable as standalone dementia diagnostic tools.
Yet, on a broader scale, emerging data suggests that using hearing aids might reduce dementia risk. A similar benefit could come from addressing vision problems.
Therefore, evaluating sensory issues in older adults could prove vital.
In the Australian study, researchers examined visual acuity and its link to cognitive decline among 2,281 participants. The findings showed that worsening vision significantly predicted lower scores in memory, attention, and problem-solving tasks.
Interestingly, social engagement played a role in influencing this relationship.
“For the first time, our study demonstrates that the association between reduced vision and overall cognitive performance might be partially explained by diminished social interactions,” Wilson explained.
“Those with poorer vision might shy away from social events due to anxiety, which could further affect their cognitive capabilities. Our findings highlight the need to maintain social connections—not just because social isolation is a known dementia risk, but also as a way to potentially lessen the effects of other risk factors, like poor vision. However, more research is necessary.”
The UK study, involving over 8,000 participants, had individuals complete a vision test—pressing a button when a triangle appeared on their screen.
At the study’s conclusion, those with slower processing times were found to have a significantly higher likelihood of a dementia diagnosis.
However, this wasn’t a precise prediction for individuals. In essence, the tests didn’t accurately determine who would develop dementia based solely on vision scores.
The authors suggested that these tests could be “incorporated into dementia risk screenings and early diagnosis alongside other cognitive evaluations.”
A recent investigation found that around one in five dementia cases in older adults related to common vision issues. This points to the potential for addressing vision problems to mitigate some dementia-related risks.
Dementia is a highly intricate condition, and it seems unlikely that any single risk factor plays a decisive role on its own.
Still, growing evidence indicates that our eyes respond sensitively to age-related damage. For example, changes visible in retinal scans can be significant predictors of mortality risk, especially considering that dementia is the leading cause of death in the UK.
The recent Commission on dementia in The Lancet advocates for making screening and treatment for vision impairment widely accessible.
“There’s a clear opportunity for dementia prevention through the treatment of vision loss,” a diverse group of experts concluded.
A previous version of this article was published in November 2025.
