Six signs in your eyes that tell you about your health

Our eyes may be the window to our souls, but they are also a window to our health. Photo / Joel Staveley, Unsplash

Our eyes may be the window to our souls, but they are also a window to our health – and we ignore eye problems at our peril.

“The back of our eye is the only place where we can see blood vessels without making an incision in the body,” says behavioural and neurodevelopmental optometrist Bhavin Shah from Central Vision Opticians. This means eyes can reveal a host of health problems, from diabetes to high blood pressure. Yet a recent Specsavers survey revealed a fifth of the population can’t remember when they had their last eye test.

Dementia

As we age, we are more likely to get cataracts. But it’s not only our sight that’s at risk – there’s also a link to developing dementia. A study in the British Journal of Ophthalmology last year found that, compared with people with healthy eyes, the risk of dementia was 11 per cent higher in cataract sufferers. Another study has shown people who have cataract surgery were 30 per cent less likely to develop dementia than people with cataracts who don’t.

Shah explains: “There are a few potential reasons why: studies show sensory impairment can lead to cognitive decline; having cataracts may lead to more social isolation, or people who have cataract surgery may be more health-aware.”

Cataracts develop as we age and the lens starts to deteriorate. “When people hit their 60s, the lens can get cloudy and lose clarity. Things aren’t as distinct, or you notice a glare around headlights.”

Cataract surgery involves “making a tiny incision and replacing the misty lens with a new one” and has a high success rate, says Shah – and although cataracts can be tolerated in early stages, surgery is recommended as soon as you start noticing symptoms. “The optimal time to have surgery is when it becomes symptomatic and starts affecting your day-to-day life,” he says. “Also, the longer you leave it, the harder it is to operate.”

Diabetes

An eye test can be a crucial first step in detecting diabetes. Although it is often asymptomatic in early stages, there may be changes in the eye. Shah explains: “High blood sugar levels affect the blood vessels, making them leaky. Sometimes we can see haemorrhages or fluid leakage at the back of the eye.” The patient may experience “floaters” in their vision or blurred vision as a result.

It’s essential to catch diabetes early before damage to organs such as eyes or kidneys becomes irreversible. In diabetic retinopathy, where the blood vessels in the retina are damaged, patients may eventually experience vision loss if it’s left untreated.

Diabetics are twice as likely to get glaucoma (where the optic nerve is damaged) and are prone to developing cataracts at a younger age. The British Journal of Ophthalmology study also showed a 61 per cent increased dementia risk in people with diabetic-related eye disease.

But, Shah says, the good news is: “If changes in the eyes are picked up early, they can be resolved and reversed.” Diabetics should keep blood sugar levels, blood pressure and cholesterol under control and take prescribed medicine, and attend their annual diabetic eye screening test.

High blood pressure

Eye tests can detect high blood pressure, as this can damage small blood vessels. Shah says: “If your blood pressure is high, it will affect blood vessels in the whole body. We’ll check the back of the eye and if we spot changes in blood vessels we will refer patients to the GP.”

If damage to the eyes is occurring, it’s also a warning sign that high blood pressure may be affecting other organs such as the heart or kidneys. If detected in time, changes can be reversed by controlling blood pressure.

High cholesterol

High cholesterol is a risk factor for heart disease – and signs of the condition can appear around the eyes and on the eyelids in the form of orange plaques called xanthelasma.

GP Thuvarahan Amuthalingam from drderme.com says: “Orange plaques are a sign of cholesterol deposits. If I see that in a patient, I’d test to make sure we’re not missing familial hypercholesterolemia, where high cholesterol runs in the family.”

Shah adds: “Some people with high cholesterol also develop a blue ring around the cornea.”

Lifestyle changes such as reducing saturated fats can lower cholesterol levels. Xanthelasma can be removed with laser surgery or liquid nitrogen.

Dry eye and myopia

Dry eye may be an indication we are spending too long on our screens. Shah says: “As we age, tear glands get dry and we get bacteria in them. It feels like something is in your eye and can be very irritating.”

Excessive screen time makes the problem worse, as we blink less – and even though the condition is usually associated with ageing, there are reports children are also suffering from it.

Worryingly, Shah says up to twice as many children are being diagnosed with myopia compared with 20 years ago. This will lead to an increase in glaucoma, macular degeneration – where vision in the middle of the eye is detected – and cataracts.

The cause? We tend to blame our genes for short-sightedness, but lifestyle is also to blame, including too much time on screens and lack of outdoor exercise and exposure to sunlight.

Shah says: “Early diagnosis is key, as preventative measures such as myopia-control contact lenses can prevent the prescription worsening.”

Life-threatening conditions

Sometimes, serious life-threatening conditions can be picked up via an eye test, especially if symptoms emerge suddenly. Having a stroke is one.

Shah says: “A patient recently called to say she’d lost some vision on one side. A visual field test showed she’d lost it on both sides, which is an indicator of a stroke. It was the only symptom she was experiencing. We sent her to hospital, where she was diagnosed with having a stroke.”

If a patient presents with symptoms such as painful eye movement, blind spots, double vision or involuntary eye movements, a GP or optician may check for multiple sclerosis. The swinging flashlight test – when a light is shone in your eye – can detect a delayed response in pupils. Steroids can be prescribed.

How to keep your eyes healthy

Experts Bhavin Shah and Dr Amuthalingam advise the following:

• Have an eye test at least every two years, and annually if you are diabetic
• Take aerobic exercise to get the blood circulation of the eyes working
• Drink lots of water to keep yourself hydrated
• Stop smoking – it can increase the risk of cataracts, glaucoma, dry eye and age-related macular degeneration
• Wear sunblock around your eyes or sunglasses to prevent damage as the skin around our eyes is the thinnest on the body
• If you have an underlying health condition, make sure you check any eye infection with a GP