A simple eye test can predict a person's risk of having a heart attack or stroke within the next ten years, a study suggests.
Researchers used artificial intelligence (AI) to analyse digital retinal photographs - images of the back of the eye that are already used to diagnose some conditions.
The technology was able to produce a personalised risk score for each patient in less than a second.
The test could one day be offered alongside blood pressure and cholesterol checks to identify more people at highest risk of disease, so they can be offered treatment earlier.
Heart experts at the University of Dundee trialled the AI software on the eye scans of people with type 2 diabetes.
Those with the condition have routine eye tests to check for diabetic retinopathy, a condition where high blood sugar levels damage the blood sugar in the retina.
Study leader Dr Ify Mordi, a research fellow at the University of Dundee and consultant cardiologist, said: 'It may be surprising, but the eyes are a window to the heart.
'If there is damage or narrowing of the blood vessels at the back of the eye, there is a good chance that will also be seen in the blood vessels further inside the body, supplying the heart, which could lead to a heart attack or stroke.'
A simple eye test can predict a person's risk of having a heart attack or stroke within the next ten years.
Researchers instructed the technology to initially look for warning signs on the images, such as blood vessel narrowing or blockages.
It was then permitted to look for any detail in the photographs, such as the size or arrangement of blood vessels, before being trained using 4,200 images.
The AI tool was able to predict the people who would go on to have 'major cardiovascular events', like heart attacks or strokes, within a decade with 70 per cent accuracy.
Dr Mordi, whose findings are published in the journal Cardiovascular Diabetology, added: 'This is a one-stop scan which is routinely performed and takes less than a minute.
'It could be an important part of the package, alongside blood pressure and cholesterol checks, in identifying people who could benefit from medication or lifestyle changes.'
The AI tool was trialled in the study on people with diabetes, as they get routine retinal scans on the NHS to check for complications affecting the eyes.
But researchers say analysis of blood vessels in the eye to judge cardiovascular risk should work for most people, and not just those with diabetes.
Professor Bryan Williams, chief scientific and medical officer at the British Heart Foundation, which helped fund the research, said: 'The more accurately we can detect someone's risk of a heart attack or stroke, the better the opportunities to prevent these happening.'
'Cutting-edge innovations, like the use of retinal scans alongside health checks, could play a role in improving risk prediction, which is important if we are to reach the British Heart Foundation's goal to prevent 125,000 heart attacks and strokes in the UK by 2035.'
'However, more research is needed to show this prediction accuracy is robust, and to determine the feasibility of incorporating retinal scans into clinical practice.'
Dr Clare Jonas, research lead at the Stroke Association, said: 'AI analyses of health data gathered through screening technology such as this eye scan have exciting potential for better early detection especially for those with diabetes who have a greater chance of having a stroke.
'Advances like these could make it easier for people at risk of stroke to take the right steps to stop it from happening.
'Whilst there are still many practical questions to answer about whether when and how AI could be used in clinical practice we hope the Government's 10 Year Health Plan will take such technological advances into account to stop more strokes from devastating people's lives.'