Only about 25 millimetres in diameter, the eye is the most important organ for finding out about the world. It has been a source of inspiration to authors, poets, artists, philosophers and physicians who have pondered and pontificated about the power of the human eye since time immemorial. Our sight is the most perfect, most delightful of our senses, working the longest without being tired or satiated with its proper enjoyment. We use our eyes constantly, reading, writing, working, watching games, movies, TV; learning about the world around us, seeing objects as far away as the stars, as tiny as a grain of sand, as deep as the deepest sentiments in our hearts. No one knows who first said: “the eyes are the windows of the soul” — the mirror, the gate, the path, the doorway, take your pick — but records of this observation have been expressed in history as far back as Plato in the fourth century BC. Cicero is quoted as saying: “The face is a picture of the mind as the eyes are its interpreter”, while Shakespeare wrote: “The eyes are the window to your soul”. It was not an original thought but a concept well known. In the Bible, Matthew, 6:22: “The light of the body is in the eye. If the eye be evil, the light within is in the darkness and how great is that darkness”. The world only exists in our eyes and one of our greatest fears is to be blind. Eyes do not lie. Often the information they convey exceeds what we ourselves wish to share: “There is a path between the eyes and the heart that does not go through the intellect,” wrote Keith Gilbert. All the countless observations did not go far enough to estimate what power the eyes hold. Physicians have discovered that the eyes can even read your fortune, so to speak. Thrilling discoveries by researchers and physicians in Europe, the US and Australia have concluded that the eyes have the ability to identify incurable diseases of the brain such as Dementia, Alzheimer's, Huntington and Parkinson's long before they occur. A non-invasive simple eye test can spot the condition easily. How does it do that? It is done through the retina that makes up the innermost layer of the wall of the eyeball, as fragile as a piece of wet tissue paper. A thinning of the retina could accurately indicate the neurodegenerative disease. Why the retina? The retina contains nerve cells just like those of the brain and is affected because it is a projection of the brain. Locked inside the skull, the brain is difficult to study and detect changes. The simple eye test can help the condition early before symptoms emerge. This could be crucial in the search of a drug as treatments are likely to be effective before the disease takes hold. A growing body of evidence resulting from the research of Dr Henri Leinonen of the University of Eastern Finland proves that the eyes are indeed windows to the brain and can diagnose not only brain diseases but other diseases like diabetes, which can ultimately cause blindness. Pathologic changes in the retina are linked to the Central Nervous System (CNS). The idea is based on the fact that the retina is an integral part of the CNS sharing neurotransmitter systems as the brain. During fetal development it matures from part of the brain and its development of nerves closely resembles that of the brain. This is indeed a breakthrough. Retinal structure and function can be easily examined with scans. Eye vision research conducted non-invasively advancement of trials from the pre-clinical to the clinical phase could be relatively fast. An eye examination serves as a potential screening tool for early diagnosis of brain diseases and should be done at least every two years since at present they can pick up on a range of conditions including high cholesterol, high blood-pressure, diabetes and increased risk of strokes. Estimates in the UK mount to a million dementia patients by 2025. These findings were published in the Journal of Alzheimer Disease & Molecular Genetics. There are precautions to take and myths to dismiss. Wearing someone else's glasses does not affect your eyesight, neither does sitting too close to the TV, but prolonged periods of computer screens without a break do. We are supposed to blink 20-30 times per minute, but on a computer it is reduced to 3-4 times, which dries out the eye and causes mutations. Dr Clare O'Donnell of the University of Manchester offers some useful tips: Remove lenses at night, take regular breaks from close distance focusing, blink properly, wash hands to reduce eye-infections and protect eyes from harsh sunlight. Children too. Never underestimate dangerous effects of the sun on your sight. Smoking, drinking alcohol and poor diet are major causes for eye diseases. Eat fish, blueberries, green leafy vegetables at least once a week. Three cups of coffee daily can help shave off dementia in women. Have regular eye-tests; they can detect amyloid related proteins early, which cause memory loss. Dr Colin Masters of the University of Melbourne says: “I can see the future five years from now with a regular check-up, if they are in the Alzheimer's path.” Those never quiet eyes, “the jewel of your body”, can see the future in your brain. Eyes cannot see without the brain. “The eyes shout what the lips fear to say.” William Henry (1774-1836)
