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Anthea Rowan

This is the 45th instalment in a series on dementia, including the research into its causes and treatment, advice for carers and stories of hope.
William Shakespeare described the eyes as the window to the soul.
It turns out that they are much more than that: they can offer a view of our overall health, and a regular eye exam can pick up a host of illnesses.
Marfan syndrome, for example, is a genetic disorder that affects connective tissue – the fibres that support and anchor the organs and other structures in the body.
It most commonly affects the heart, eyes, blood vessels and skeleton. It is visible in sufferers’ eyes as long stringlike tissues that hold their lenses in place. This alerts doctors to check for aortic wall weaknesses in the heart.

Thyroid disease is evident in a bulging eye. Cancer of the eye can be seen as black spots at the back of the eye – a growing and potentially fatal melanoma if not spotted early.
The signs of high blood pressure might appear in the eyes as bends or tiny tears in the small vessels of the eye.
Blurred vision usually means you need a new prescription for lenses or glasses – or that you need to start wearing glasses. But it can also point to things like diabetes. In one study, 73 per cent of the diabetic patient participants being monitored reported blurred vision.
The retina, at the back of the eye, might show the warning signs of heart disease; stroke risk can be found in the eye, too – blocked blood vessels in the eye could indicate blocked blood vessels in other parts of the body.
Brain illnesses and injuries can be spotted in the eye – sometimes early enough to make a big difference. Because the optic nerve is an extension of the brain, an eye exam may flag a neurological condition.

As Dr Thomas Wilcockson, a senior lecturer in psychology at Loughborough University in the UK observes, the eyes are “the window into the brain”. And, he adds, “measuring the way we control our eyes may provide us a non-invasive way of determining brain health”.
Wilcockson and his team recently published a study that found there could be clues in eyes – “a loss of visual sensitivity” – that could predict dementia 12 years before it manifested in those awful symptoms of decline.
The research – which included almost 9,000 participants who were followed up for many years – began with a visual sensitivity test: they had to press a button in response to a particular image forming on a screen. The data showed that those who responded slowly went on to develop dementia later.
Amyloid beta, one of the markers of Alzheimer’s disease, is thought to begin by damaging the brain near regions associated with controlling eye movement, Wilcockson says. That is why deficiencies in eye movement may be an early marker of Alzheimer’s.
What is the link between eye movement and brain health and memory? It is thought that horizontal eye movements boost memory by stimulating communication between brain hemispheres.
Wilcockson explains: “Rapid eye movements might force these hemispheres to work together, leading to better memory retrieval.”

Some studies have found that this sort of rapid – and repetitive – horizontal eye movement might improve autobiographical memory.
That may explain why people who watch more TV and read more have better memory and less dementia risk than those who do not, he suggests.
While eyes may help to predict brain health – even prevent the brain drain that comes with dementia – being able to see well is both necessary for, and extends, brain health.
Untreated visual loss is the latest modifiable risk factor to be added to the updated Lancet Commission’s list of dementia risk factors last month. Whether watching a film or reading a book to benefit from that repetitive, rapid eye movement, you obviously need good vision – or glasses.
What does “untreated” visual loss mean? Professor Gill Livingston, an author of the Lancet reports, says it refers to “anything which impairs vision”. Anything.

Untreated visual loss is a risk for dementia, she says, because it robs the brain of stimulation through reading or watching a movie or television, and also because it restricts physical and social activities.
Livingston says the global prevalence of avoidable vision loss and blindness, including common sight problems for which glasses are prescribed, in adults aged 50 years or older, is estimated to be 12.6 per cent.
It is much more prevalent in low- and middle-income countries than in high-income countries where vision tests are often more easily available, she adds.
Of course, the primary reason for a sight test is just that: to check your sight and the health of your eyes. Many people’s sight is improved with spectacles (if I did not have mine, I would not be able to read, drive, watch TV or work). Sight is often saved with – for example – an early diagnosis of intraocular pressure which could lead to glaucoma; this is easily treated with drops but, if left untreated, can lead to blindness.
Cataracts are another common condition that might be picked up in the eye exam.
We want to demonstrate that eye movements can be an effective way to predict dementia. We aim to develop cheap and efficient ways of monitoring eye movements
Dr Thomas Wilcockson, senior lecturer in psychology, at Loughborough University
These may begin to form when you are in your 40s – the proteins in the eye lenses start to break down, which causes the lens to cloud. They are common; more than half of all Americans have had a cataract removed by the time they are 80.
In Hong Kong, at the end of June 2024, there were 69,438 people booked for cataract surgery on the waiting list in the public hospital system, with a waiting time of 10 to 31 months depending on the district.
That simple surgery may help protect brains: one US study found that people who had cataract extraction surgery had significantly reduced dementia risk compared with those who did not.
This is what drives Wilcockson’s research.

“We want to demonstrate that eye movements can be an effective way to predict dementia,” he says. To that end, he adds: “We aim to develop cheap and efficient ways of monitoring eye movements so that these measures can be used more widely.
“Then, with lifestyle change interventions, we may be able to delay or even prevent dementia progression.”
And to do that you need good sight.
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Your eyes are windows into your physical and mental health, and an eye test can reveals symptoms of multiple conditions, from high blood pressure to diabetes and dementia. Photo: Shutterstock

An eye exam can reveal much about a person’s overall health, even whether they have high blood pressure. Photo: Shutterstock

“Measuring the way we control our eyes may provide us a non-invasive way of determining brain health,” says Dr Thomas Wilcockson, a senior lecturer in psychology at Loughborough University, in the UK. Photo: Loughborough University 

People who watch more TV and read more have better memory and a lower dementia risk than those who do not, a new study suggests. Photo: Shutterstock

There could be clues in eyes – a loss of visual sensitivity – that predict dementia 12 years before it manifests in memory loss. Photo: Shutterstock

Thomas Wilcockson performs an assessment of a participant’s eyes, using tools to track eye movement. Photo: Loughborough University 

Ozempic, other weight-loss drugs help with heart attack, stroke, fertility. Dementia next?

Many of the new weight-loss drugs can by extension alleviate other health conditions. Photo: Shutterstock

Ozempic and similar new weight-loss drugs also lower the risk of heart attack, stroke, kidney and liver disease, and some increase fertility. The mechanism they use to target parts of the body could be applied to dementia treatment, researchers hope. Photo: Shutterstock                                                       

With more than a billion obese people on the planet, Clemmensen says at least 10 effective drugs that work in different ways are needed. Photo: Shutterstock

There have been reports of a so-called Ozempic baby boom after many women who were overweight and believed to be infertile became pregnant after losing weight with the help of new weight-loss drugs. Photo: Shutterstock 

Christoffer Clemmensen, of the Novo Nordisk Foundation Centre for Basic Metabolic Research at the University of Copenhagen, says weight-loss drugs introduced recently are not perfect. Photo: Christoffer Clemmensen

Christoffer Clemmensen’s team is researching how they might use the same GLP-1 receptor found in new weight-loss drugs to “smuggle” a drug into mice brains that targets neurons responsible for appetite control. Photo: Shutterstock

Ageing speeds up at 2 points in your life. Experts share things you need to be aware of

A study shows increases in the rate of ageing of our bodies at two points in our lives. One effect is that we become less effective at metabolising the caffeine in coffee. Photo: Shutterstock

People become less effective at metabolising alcohol at the age of about 40 – and even less so at age 60 – a study suggests. Photo: Shutterstock

Muscle injuries were found to be more common at the ages of about 44 and 60 in participants in the study. Photo: Shutterstock 

Sleeping in on weekends could help protect your heart, study on compensatory sleep says

Catching up on sleep at the weekend could lower your risk of developing heart disease by nearly 20 per cent, new research finds. Photo: Shutterstock

Sleeping in on the weekends could lower your risk of developing heart disease by nearly 20 per cent, new research finds. Photo: Shutterstock

The study also looked at a subgroup of people with daily sleep deprivation – defined as having less than seven hours of sleep a night. Photo: Shutterstock

Lifestyle

Health & Wellness

Health

An eye test can reveal many conditions, from high blood pressure to thyroid disease and diabetes, and predict dementia 12 years in advance


An eye test can reveal many conditions, from high blood pressure to thyroid disease and diabetes, and preserving good eyesight can stave off dementia.


Dementia

Ageing society

Medicine

How to age well