It's long been said that the eyes are a window to the soul. Some people also believe that our eyes are actually a window to our physical health. Studying someone's eyes to find out about their well-being is called iridology and reporter Michael Slater sets out to see how effective it is.
Iridologists believe markings in the iris reveal inherited conditions that may lead to physical and emotional disorders.
Over many years, iridologists have "mapped" segments of the iris to correspond with various internal organs, and their ailments.
According to iridologist Anthony Middlemiss, it's about uncovering health history; not diagnosing the present.
"I find it a useful starting point in consultation," he says. "It helps jog their memory about things that have happened in their past or their parents' past and it helps to give us a holistic approach in assessing a patient's health."
Sarah Bebb swears by iridology. She first saw an iridologist four years ago, who examined her eyes, and made health and lifestyle suggestions based on what he saw.
"He actually said that I had a lot more stress lines than I should have for a normal person," recalls Sarah. "My liver needed some help. I also needed to change my diet."
Sarah made the changes and is now a convert.
"My whole outlook my vibrancy, energy levels, everything were the highest, I'd say, that they've ever been," she says.
Michael is going to put iridology to the test by asking Anthony to find ailments in him, and two other people he's never met.
Anthony examines a sceptical Michael's eyes.
Anthony asks Michael if there's a history of lung problems in his family. There's not that Michael knows of, and Anthony adds that these "areas of loose fibres" in his eyes aren't greatly significant.
What else can Anthony come up with?
"One of the most significant things in your eyes, Michael, is you've got a white overlay," says Anthony. "A lot of iridologists believe that's a uric acid eye. And that gives you a predisposition to arthritis and rheumatoid conditions.
Anthony's on the money with that one. "About three years ago I had a bout of reactive arthritis, which ended up finishing my cricket," confirms Michael.
Anthony also picks up a couple of other family conditions in Michael's history.
Michael's medical history is somewhat of an open book, however, thanks to his cricketing days, so to really put iridology to the test, we've got two more candidates for Anthony to examine.
Brienne Czeref is 22 years old and she's just finished her degree in Food Technology. Jordan Maloney's 24 and he's studying medical science.
Both Jordan and Brienne have health issues that Anthony knows nothing about.
"When I was born I had a urinary reflux," says Brienne. "Basically, my urine would flush back up into my kidneys."
"I suffered a back injury years ago," says Anthony. "I do have some persisting symptoms from that."
Dr David Cockburn would say that Jordan and Brienne are wasting their time with iridology. He's a retired academic who's published research on its usefulness in diagnosing medical conditions.
"In my view iridology is a total nonsense, but it's pretty harmless, provided it's not taken too seriously," he says. "It's a bit like reading tealeaves in teacups, reading palms of hands or chicken's entrails."
Anthony examines Jordan's eyes and says that a family history of anxiety may be indicated, which Jordan says he's not a hundred percent certain of. Not a great start.
Anthony then picks up on a significant spot right in the middle of the lungs. It turns out that Jordan had pleurisy around the age of 14, which took him out of school for three weeks.
"You've also a large mark in the back area," observes Anthony. "Have you ever suffered a back injury or have a family history of back injury?"
"At about the age of 13, I did injure my back, rollerblading," confirms Jordan.
Two out three isn't bad, but Dr Cockburn is not convinced.
"If you make enough diagnoses you'll get one of them right down the track," he says. "If you tell a patient they've got 30 things wrong with them, one of them is bound to be right."
Anthony examines Brienne. He finds a dark outline around the outside of her eye.
"The term for that is termed a scurf rim," he says. "And that's associated with poor circulation; not sweating a lot they're the most common things people say."
Brienne says that she does have poor circulation and doesn't sweat much
Anthony then asks about discolourations pertaining to the adrenal and kidney area, groin and pelvis. Brienne confirms that she had urinary reflux as a child.
Our two guinea pigs have given their iridology experience the thumbs up.
"Actually he was really, really spot on. I can't believe how well it went, actually," says Brienne.
"It was really quite interesting," says Jordan. "He outlined a lot of my predispositions, particularly in my situation, I was quite impressed. Especially mentioning my back."
Michael's more convinced that iridology might be useful as a sort of medical memory jogger; things to watch out for, so to speak.
Opponents like Dr David Cockburn still disagree. He says the only way patients can fix their medical problems is with a proper diagnosis not iridology.
"Not only does it waste people's time and money, but it can delay a proper diagnosis of whatever it is that they're seeking help for," he says.
Make up your own mind, but one thing's for sure; the human eye is a pretty wonderful piece of equipment. It's how we see the world outside us and, if you believe the iridologists, the world within as well.
Regardless of whether you believe in iridology or not, it's only ever intended as a starting point in health care. As always, if you're concerned about a problem, go see your GP.
Eye colour is determined by melanin, the same chemical that colours your hair and skin. More melanin means brown eyes; less and they get lighter, like blue. If one parent has brown eyes and the other blue, generally the child will have brown eyes because that gene is dominant. It doesn't always happen that way however, and geneticists are yet to work out why.
It's not uncommon for people, particularly couples, to share their glasses, but using someone else's glasses is not a great idea because everyone's prescription lens is different. A short time in the wrong glasses isn't a major problem, but it can lead to temporary eye strain. Prolonged use might cause damage, as your eyes try to adjust to the inappropriate lens.