Is loss of vision linked to dementia? Neurologists explain why getting your eyes checked is a brain health decision

Loss of vision with age can affect the cognitive functioning of the brain if left untreated for long, according to large scale observational study.

The importance of getting eyesight checked can hardly be understated. However, neurologists and content creators Drs Ayesha and Dean Sherzai took to Instagram on March 26 to explain how taking care of the eyes has been linked to taking care of the brain and lowering dementia risk.

“The Lancet Commission on Dementia cited a meta-analysis of 14 prospective cohort studies following more than six million adults, cognitively intact at baseline,” shared the neurologists. “People with untreated vision impairment had a 47 percent higher risk of developing dementia.” They did note that the data were observational and only showed association without proving causation.

“A vision problem is not a dementia diagnosis,” highlighted the neurologists. “This finding is about untreated, uncorrected vision loss, the kind that slowly reduces your ability to read, drive, socialise, and move through the world.”

Connection between vision and cognition

The neurologists explained that there are three ways in which damaged vision affects cognition. They are as follows:

• Sensory Deprivation: Less visual input means more cognitive load for everyday tasks. Over time, neural reserve erodes.
• Downstream isolation: Untreated vision loss reduces driving, socialising, reading and exercise - all independent dementia risk factors.
• Shared pathology: The retina is brain tissue. Amyloid and tau changes seen in Alzheimer's may appear in the retina first.

Does inherent low vision affect brain health?

Not all people start to lose their vision only when they grow up. It is becoming increasingly common for children to have spectacles as a result of having imperfect vision. However, the aforementioned study does not link their condition to dementia.

As the neurologists stated, “People born with or who develop vision loss early often build remarkable cognitive resilience over time. The brain adapts. Other sensory and cognitive systems strengthen.”

“This finding is specifically about late-life vision loss that goes untreated, not lifelong visual impairment where the brain has already reorganised around it,” they added.

Is cataract linked with cognitive decline?

One of the conditions that leads to a drop in eyesight among adults is the formation of cataracts. The study has revealed that cataract surgery is associated with a 25 percent lower risk of cognitive decline compared to uncorrected cataracts. While the finding is observational, it is still worth noting, shared the neurologists.

Steps to preserve vision and cognitive health

According to the neurologists, the only step that one can take to mitigate risks is getting the eyes tested. It is better to treat correctable conditions and not leave them unaddressed, thinking that it is just a normal part of ageing. Protecting one system protects the other.

Note to readers: This article is for informational purposes only and not a substitute for professional medical advice. Always seek the advice of your doctor with any questions about a medical condition.

This report is based on user-generated content from social media. HT.com has not independently verified the claims and does not endorse them.