What Research Is Learning About Vision, Hearing and Cognitive Health

In this series, we've been looking at vision and hearing through a wider lens. Not simply how well we see or hear, but what those senses allow us to keep doing and experiencing as we age.

There is another reason this conversation matters. Researchers are increasingly looking at vision and hearing as part of a much bigger picture of healthy ageing, including our cognitive health. And some of what they are learning deserves attention.

What does the research tell us?

In 2024, the Lancet Commission on dementia prevention, intervention and care identified 14 potentially modifiable risk factors associated with dementia. Hearing loss was already among them. In its 2024 update, the Commission added two more: untreated vision loss and high LDL cholesterol.

Taken together, the Commission estimates that around 45% of dementia cases could potentially be delayed or reduced by addressing the 14 identified risk factors across the course of life.

That figure needs to be understood carefully. It does not mean that 45% of dementia is caused by vision or hearing loss. Nor does it mean that correcting your vision or using hearing aids will prevent dementia. Vision and hearing are two factors within a much larger and more complex picture.

But their inclusion is significant. It places our senses within a conversation about healthy ageing that extends beyond simply seeing and hearing well.

Vision is also being studied in a wider health context

Research published in the American Journal of Ophthalmology in 2026 adds another dimension. The study found that visual impairment was associated with a 36% increase in all-cause mortality, with the association driven primarily by non-cardiovascular causes.

Again, this is an association. It does not tell us that visual impairment causes earlier death or that correcting vision changes that outcome. What it does show is that researchers are increasingly examining vision as part of a broader picture of health rather than as an isolated measure of eyesight.

These are different studies, examining different outcomes. But together with the growing body of research around hearing, they raise an important question: have we been thinking about our senses too narrowly?

A possible fifth pillar of healthy ageing?

We already know that connection, movement, diet and purpose matter as we age. Perhaps vision and hearing deserve a more prominent place within that conversation too.

Not as a formally established “fifth pillar”, and not because the evidence allows us to make claims it doesn't support. But as an emerging idea worth exploring.

If seeing and hearing contribute to our ability to stay connected, independent, active and engaged, and research is increasingly examining their relationship with wider health outcomes, there is a case for paying greater attention to our senses as part of how we think about ageing well.

It's this wider conversation that Wellington Eye Clinic and Beacon Audiology are exploring together through Lifestyle Vision & Hearing. As sister clinics specialising in vision and hearing, their collaboration in Cork creates an opportunity to consider both senses as part of the same healthy-ageing conversation, while maintaining the distinct clinical expertise each requires.

And that conversation becomes particularly important when we turn to dementia and Alzheimer's disease.

What the evidence tells us, and what it doesn't

The inclusion of hearing loss and untreated vision loss among the Lancet Commission's modifiable dementia risk factors has understandably attracted attention. But headlines can make complex research sound much simpler than it is.

What does “modifiable risk factor” actually mean? How strong is the evidence? What is the difference between an association and a cause? And can looking after our vision or hearing actually reduce an individual's risk of developing dementia? Those questions deserve careful answers.

Frequently asked questions

Is hearing loss associated with dementia risk?

Yes. Hearing loss is included among the potentially modifiable risk factors identified by the 2024 Lancet Commission on dementia prevention, intervention and care. This is an association and should not be interpreted as proof that hearing loss causes dementia.

Is vision loss associated with dementia risk?

The 2024 Lancet Commission added untreated vision loss to its list of potentially modifiable dementia risk factors. This does not mean that treating vision loss has been proven to prevent dementia.

Can treating vision or hearing loss prevent dementia?

The evidence cited here does not support that conclusion. Vision and hearing form part of a much wider and more complex picture of dementia risk. We explore this distinction in the next article.