What Your Eye Health Says About Your Risk of Dementia

• A new study found a link between vision impairments and dementia risk in older adults.
• The study does not prove causation, but experts note that previous research has seen patients' cognitive function improve after improved eye health, so the correlation is worth considering.
• Experts recommend people prioritize regular eye care, especially those with a family history of an eye disease or people over the age of 65.

Vision impairments are linked to a greater risk of dementia, a new study finds.

Growing evidence demonstrates the connection between eye health and brain health, specifically how vision impacts cognitive function. The new study, published in JAMA Ophthalmology, showed that people with untreated visual impairments have a higher chance of developing dementia.

Researchers reviewed the 2021 National Health and Aging Trends Study, examining data from approximately 3,000 people, age 71 and older. Slightly over half of the participants were female and about 75% of identified as non-Hispanic White.

Study author Olivia Killeen, MD, MS told Health that three types of visual impairment were studied: near vision (reading vision), distance vision (used for driving or watching TV across the room), and contrast sensitivity (the ability to distinguish objects of similar color as their surroundings).

All three types of visual impairments showed a greater correlation with dementia than participants without any visual impairment.

“Impairments in each of these were associated with dementia, and having multiple types of visual impairments was more closely associated with dementia,” said Killeen, who is a clinical lecturer of ophthalmology and visual sciences at the University of Michigan.

While there are many well-known reasons for dementia, vision isn’t typically the first that comes to mind.

“What makes the study interesting is that the persons affected probably don’t realize that their vision issues may be connected to dementia, even though it makes sense that uncorrected vision problems could lead to dementia,” Vicente Diaz, MD, chief of Ophthalmology at Bridgeport Hospital told Health.

This new research further emphasizes that all aspects of an individual’s health are connected.

“Living in a blurry world increases dementia risk but the patients don’t necessarily realize it,” Diaz said. “The reverse is also true, sometimes after cataract surgery or other interventions where we bring vision back, patients’ cognition can improve.”

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A Correlation Between Visual Impairment and Dementia

It is unknown if visual impairment came before dementia, causing it, or if the two are simply correlating issues.

“This study found a correlation between visual impairment and dementia, but we do not know which came first,” Killeen said.

While doctors are still exploring the relationship between eye health and brain health, sensory rehabilitation can be a good place to start.

“It must be emphasized that in no way did this study demonstrate cause and effect,” Howard R. Krauss, MD, a surgical neuro-ophthalmologist and director of Pacific Neuroscience Institute’s Eye, Ear & Skull Base Center at Providence Saint John’s Health Center in Santa Monica, CA, told Health.

While the study does not prove causation or acceleration between visual impairment and dementia, experts agree it’s worth being aware of the correlation.

“On the other hand, it is sensible to believe that sensory deprivation may further impair cognition or mood in those with dementia, and there is benefit in providing sensory rehabilitation (sight, hearing, olfaction, etc.) in an effort to improve quality of life for those with dementia,” Krauss said.

How Eye Health Might Impact Brain Health

The only way to know the status of your eye health and brain health is to visit a healthcare professional.

Arman Fesharaki-Zadeh, MD, a behavioral neurologist at Yale New Haven Health, explained the discussions pertaining to eye health and cognitive health should ideally start from the primary care physician (PCP) regular annual assessment sessions.  

He noted that it’s often helpful to include a patient’s family members and loved ones in conversations like this, since they can bring a more objective view on the patient’s visual and cognitive symptoms.

“If such accounts are provided, patient’s PCP can initiate further pertinent vision and cognitive work up via referral to the appropriate specialist provider,” he said.

Interestingly, there is research to show a link between vision improvement (as seen through cataract surgery) and a decreased dementia risk.

“It is difficult to say that one’s intrinsic eye health affects the brain in a structural way, however, there is some evidence that cataract surgery is associated with lower risk of dementia development, suggesting that interventions to improve vision in older adults may help to maximize cognitive function,” Ore-Ofe Adesina, MD, associate professor of ophthalmology with McGovern Medical School at UTHealth Houston told Health.

He emphasized that the study indicates that visual impairment is associated with a higher prevalence of dementia among older adults.

“Therefore, if someone is experiencing significant visual impairment or has been diagnosed with an eye condition, it may be prudent to consult a healthcare professional, such as an ophthalmologist or neurologist, to discuss potential connections between their eye health and brain health,” he said.

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Maintaining Proper Eye Health

Experts agree that vision care should be a priority.

“The American Academy of Ophthalmology recommends that people 65 and older get routine eye exams every 1–2 years,” Killeen said. “Patients should also see their eye doctor whenever they have a problem, like blurry vision, eye pain, or eye redness.”

Sometimes people do not visit the eye doctor because they assume that losing vision is a normal part of aging. But it’s not. Most eye problems are treatable, Killeen explained.

Ask your eye doctor if you have signs of common eye problems that impact older people, like cataracts, glaucoma, and macular degeneration.

Also, “if there is an eye disease that runs in the family, definitely ask about it at the eye exam,” Diaz said. “If the patient has other medical conditions they should ask about how those impact the eyes. Any eye symptoms that are new should warrant consultation by an ophthalmologist.”

Another important factor to take into consideration is how vision is one of the main ways we process information.

“Memory and cognitive functioning is predicated on encoding and gathering of environmental information, and vision plays a key role in this process,” Fesharaki-Zadeh explained.

“Individuals are highly encouraged to remain vigilant and address visual concerns, which might arise in various settings including driving, walking as well as looking at display devices during their annual PCP visits,” he said.

Ideally, PCP physicians can further facilitate these discussions by including brief vision and cognitive screening for individuals 65 years or older, or younger patients with reported symptoms, Fesharaki-Zadeh said.

Asking Important Eye Health Questions

To better prioritize eye health, Adesina recommends people discuss the following with their eye care professional:

• Schedule regular eye exams
• Ask about the frequency of eye exams based on individual circumstances and risk factors
• Inquire about any specific concerns or symptoms related to vision
• Discuss family history of eye diseases
• Inquire about lifestyle factors that may affect eye health
• Follow recommendations for protecting eye
• If diagnosed with an eye condition, ask about treatment options, potential impacts on vision, and any associated risks or precautions

It’s important to note that these are general suggestions, and specific recommendations may vary depending on individual circumstances. Consulting with an eye care professional is crucial for personalized advice and guidance regarding eye health.