Your peepers can reveal a lot about the state of both mind and body…

EYES, they say, are the windows to the soul but scientists have discovered they also reveal a lot about our physical and mental health. They could even predict your child’s risk of a heart attack in later life.

Children who spend hours in front of a computer or television show changes in blood vessels in their eyes which are associated with an increased risk of heart disease in later life, an Australian study of 1,500 youngsters found.

A second study at the University of Maryland in the US, found that when volunteers were shown photographs of people’s eyes and asked to rate how healthy and happy they were, they thought those with red eyes were most likely to be poorly or feel low.

It makes sense as our eyes redden when we’ve been crying or have a hangover but researchers also found seeing a friend with red eyes makes us feel uncomfortable and may even make us well up in sympathy.

Winfried Amoaku, chairman of the scientific committee of the Royal College of Ophthalmologists, explains: “There are a number of diseases we can detect from the eye, including jaundice and anaemia as well as high cholesterol.”

Experts believe as many as one in four people with undiagnosed diabetes would have the condition picked up if they went for an eye test.

Eyes provide an opportunity to view internal blood vessels and nerves as they work. But eye examinations should not be confused with iridology – the alternative therapy based on the belief eyes can be used to diagnose conditions.

Iridologists claim different parts of the iris correlate with areas of the body and that changes to the iris indicate changes to that organ or body part. When it was put to the test by researchers at Australia’s University of Melbourne, iridologists were unable to detect any difference in before and after photographs of people who had developed serious illnesses.

However they did mistakenly “diagnose” a problem based on photographs taken two minutes apart which were included as a control.

Here are some of the ways your eyes really can reveal the state of your health.

HEART-RINGING

A grey or white ring around the outer edge of the iris – the coloured part of your eye – could be a warning of heart problems, stroke and diabetes.

The condition, known as corneal arcus, is common in old age and is considered normal for anyone over 70 but in younger people it could be caused by excess cholesterol, a major risk factor for cardiac disease.

A study at the Singapore Eye Research Institute found a connection between corneal arcus and inflammation which also increases the chances of developing heart disease and may be a factor in cancer. Scientists at the Columbus Research Foundation in the US ran health checks on 2,000 volunteers with a visible grey-white ring around their eyes. They found 88 per cent of them had high blood sugar, 66 per cent were overweight and 64 per cent had high blood pressure.

The association is so strong that Dr Steven Leichter, medical director of the foundation, believes: “Comprehensive eye exams should be used as a screening for prevalent metabolic conditions.”

THE LOOK OF LOVE

Our eyes can’t keep a secret when it comes to the opposite sex.

Several studies, including one at Edinburgh University, have shown that when we are attracted to someone our pupils dilate, making them look larger. This makes us more attractive. In women, the biggest change in pupil size comes when they are at the most fertile phase of their menstrual cycle.

OVERACTIVE THYROID

Wide, bulging eyes are a sign of an overactive thyroid, the gland which regulates our metabolism.

When this gland in the neck goes into overdrive and produces too many thyroid hormones, muscles at the back of the eye become swollen. This pushes the eyeballs forward making them appear much more prominent.

Occasionally this swelling presses against the nerve which sends signals from the eye to the brain and can lead to double vision.

Other warning signs include eyes feeling sore and gritty, light sensitivity and puffy eyelids.

Treatment focuses on rebalancing levels of thyroid hormones. Symptoms such as soreness can be relieved with hypromellose drops, artificial tears which lubricate and soothe the eye.

Comedian Marty Feldman’s trademark bulging eyes were caused by Graves’ disease, a condition that causes overactive thyroid.

DRY EYES

Lack of sleep and dehydration are the most common causes of dry eyes but it may also be the result of vitamin A deficiency.

Night blindness is another tell-tale sign which shows there is some truth in the old wives’ tale that vitamin A-rich carrots are good for vision.

Dieters who stick to a very low-fat regime are the most likely to be low in vitamin A as both forms, retinol and carotene, are fat-soluble and our bodies need some lipids to absorb them effectively.

Another condition which can cause dry, gritty eyes is Sjogren’s syndrome, an immune system malfunction associated with rheumatoid arthritis.

YELLOW PERIL

When the whites of the eye take on a yellow tinge it indicates jaundice and a problem with the liver.

The liver takes toxins and waste materials out of the bloodstream, breaking them down and then eliminating them via the intestine. If it is not working properly then waste, such as bilirubin, builds up in the bloodstream.

Bilirubin is produced when red blood cells die and it is constantly being released as part of the body’s renewal and repair mechanism.

If the liver is not able to process this waste, it accumulates in the bloodstream and turns the skin and eyeballs yellow or, if concentrations are very high, brown.

Jaundice itself is not dangerous but can be a sign of a potentially life-threatening problem such as cirrhosis, liver cancer or hepatitis. A blocked bile duct or anaemia are also possibilities. Jaundice is common in newborns with 65 per cent of infants having it to some degree in their early days. It is usually resolved with light therapy.

DANGEROUS DISTORTION

If straight lines start to look wavy or distorted you may be developing age-related macular degeneration (AMD).

Other warning signs are a slight smudge in your sight, difficulty reading small print and being sensitive to light.

There are two forms of AMD, wet and dry, so-called because of what happens within the eyeball. Dry AMD is more common and comes on slowly. Wet AMD develops quickly and involves the growth of tiny blood vessels which scar the retina.

AMD is the most common cause of blindness in the UK and affects one in 50 people over the age of 50 and one in five over the age of 85.

Risk factors include a family history of the condition and smoking but a diet high in antioxidant vitamins has been proven to reduce the danger.

A 10-year study by the American National Institutes of Health which focused on volunteers at high risk of developing the condition, found a combination of vitamin C, vitamin E, beta-carotene and zinc cut the danger by 25 per cent.

The only supplement to contain the same combination used in the study is Bausch+Lomb PreserVision, £14.95 for a 30-day supply.

SEEING SPECKS

Don’t worry if you see tiny little specks and lines in front of your eyes. They are called floaters and are perfectly harmless.

However have your eyes checked if a lot of floaters suddenly appear or you experience flashes of light as this can be a sign of a detached retina.

TWITCHY EYELIDS

If your eyelids twitch or go into spasm it’s a sign you need to slow down. Stress and tiredness are the most common causes.

Too much caffeine can cause problems, so cut back on intake. Eye strain can also be a factor so take short breaks if you use a computer for long periods or enjoy hobbies such as needlework. Looking away and focus on something in the distance.