September/October 2019 Newsletter
EYES ON DIABETES
Diabetes is a disease that affects the body's ability to produce or use insulin effectively to control blood sugar levels. It can cause damage to many parts of the body including the heart, kidneys and blood vessels. The eyes are particularly vulnerable to diabetic damage because the tiny blood vessels in the retina at the back of the eye are sensitive to fluctuations of the blood sugar levels in the body. The eyes provide an unobstructed view of the blood vessels on the retina and the damage that may be present due to diabetes. This view of the blood vessels is not visible in other areas of the body because it is blocked. During a dilated eye examination, optometrists are often the first professionals to detect blood vessel changes and suspect the presence of diabetes before symptoms appear. With early detection being the key to effective management, regular visits to your optometrist are important.
Diabetic eye disease is a group of eye problems that can affect people with diabetes. These conditions include diabetic retinopathy, diabetic macular edema, cataracts, and glaucoma. Often there are no early symptoms of diabetic eye disease and no visual changes as the damage occurs gradually. Over time there could be vision loss and even blindness. When symptoms do occur, they may include blurry or wavy vision, frequently changing vision, dark areas in vision or vision loss, poor colour vision, spots or floaters, or flashes of light. If you have any of these symptoms make an appointment for an eye examination. See your optometrist immediately if you notice sudden changes to your vision, including more frequent flashes of light or many more floaters than usual, or if it looks as though a curtain is pulled over your eyes. These changes in your vision can be symptoms of a detached retina, which is a medical emergency.
Diabetic retinopathy is a condition in which blood vessels in the retina swell, leak or close off completely, or when new blood vessels grow. There are various stages of the condition. In early nonproliferative diabetic retinopathy blood vessels can weaken, bulge, or leak into the retina. As the disease progresses the blood vessels begin to lose their ability to transport blood and essential nutrients to the retina. If it gets worse, some blood vessels close off, which causes new blood vessels to grow, or proliferate, on the surface of the retina. These abnormal vessels are fragile, making them likely to bleed or break. Resultant scar tissue may pull the retina away from the back of the eye, resulting in serious vision problems if left untreated.
One of the consequences of diabetic retinopathy may be macular edema. As a result of the build-up of leaking fluid there may be swelling on the macula, the central area of the retina which is responsible for clear vision and colour vision. Initially it may be asymptomatic, but there is a gradual loss of central vision which is usually irreversible. The earlier it is diagnosed, the sooner it can be effectively managed.
While cataracts are a common condition which can occur in anyone, excess blood sugar may cause them to develop earlier and progress more rapidly in people with diabetes.
Glaucoma is a group of eye diseases that damage the optic nerve due to elevated eye pressure. The risk for glaucoma is doubled in people with diabetes, who may also develop neovascular glaucoma, a less common condition which causes new blood vessels to grow over the iris (the coloured part of the eye), blocking the normal flow of fluid and interfering with vision.
If blood sugar levels change quickly or fluctuate often, it can affect the shape of the lens of the eye, causing blurry vision. It is advisable to wait before getting new glasses because vision generally returns to normal once the blood sugar level stabilises.
If you have diabetes and become pregnant, it is possible that eye problems may develop. If there is already diabetic retinopathy, it can become worse during pregnancy. Visit your optometrist regularly to monitor your vision and treat problems that may occur. Although you may feel that your eyes are fine, there are no warning signs of diabetic eye disease in the initial stages, and the only way to be sure is by having a dilated eye examination.
The fundamental treatment of diabetic eye disease is the management of blood sugar levels. Although treatment cannot restore lost vision, it can help slow the progression of the disease. There are a number of options which are used to treat diabetic eye diseases either separately or in combination, depending on the stage of the disease. Medication to block the growth of abnormal blood vessels and stop fluid leaks can stop further vision loss and may improve vision in some cases. Laser treatment seals leaking blood vessels and reduces the build-up of fluid and swelling by creating tiny burns inside the eye. In cases of severe bleeding or scar tissue, surgery may be performed.
Take responsibility for the protection of your vision by following a healthy lifestyle. Remember the ABC of managing diabetic eye disease. It is ASYMPTOMATIC in the early stages; if you know you have diabetes don't wait for visual symptoms to emerge, have an eye examination. The key to effective treatment is early detection and treatment. BOOK appointments with your optometrist regularly, either once a year or as recommended by your optometrist. CONTROL blood sugar levels; treatment of eye disease goes hand in hand with management of blood sugar.
If you already have some vision loss from diabetes, discuss with your optometrist how best to deal with this. Special eye care professionals can help you manage vision loss that cannot be corrected with glasses, contact lenses, medicine, or surgery. Special devices and training may help you make the most of your remaining vision so that you can continue to be active, enjoy hobbies, socialise and live an independent life.
Dry eye is a common condition that occurs when tears are unable to provide adequate lubrication for the eyes, for various reasons. There may be insufficient tears or the tears that are produced may be of poor quality. The tear film has three basic layers, namely oil, water and mucus. Problems with any of these layers can cause dry eyes or there may be an imbalance in the composition of the tears. Dry eyes feel uncomfortable and can make it difficult to perform certain daily activities such as reading or driving. Symptoms include a stinging, burning or scratchy sensation, stringy mucus in or around the eyes, sensitivity to light, redness, blurred vision and eye fatigue. A typical symptom of dry eyes is excessive watering of the eyes. This may seem like a contradiction but is in fact a reflex reaction of the eyes to the lack of moisture and feeling of eye irritation, causing them to send a message to the brain for more moisture. Although there is a flood of tears, they are mostly made up of water which is not able to prevent evaporation of tears and provide long term relief by lubricating the eyes effectively.
A number of factors can influence the development of dry eyes. Although it can occur at any age, it is more common in older people as tear production tends to decrease as part of the normal aging process. Women are particularly susceptible due to the hormonal changes that occur at certain times in their lives, such as pregnancy and menopause. Chronic medical conditions, including diabetes, rheumatoid arthritis, thyroid disease and lupus often affect tear production. Dry eye can be one of the side effects of some medications, such as antihistamines, decongestants, antidepressants, hormone replacement therapy, birth control tablets and some drugs for acne and high blood pressure. A vitamin A deficiency can reduce tear production.
Dry eye is a complex condition, and treatment has traditionally treated the symptoms, focusing on lubrication of the eyes and control of inflammation. There are a number of treatment options. Some treatments aim at improving tear quality, while others prevent tears from draining too rapidly from the eyes. Regular use of over the counter eye drops, gels, artificial tears or prescription eye drops or ointments can lubricate and soothe the eyes in people with mild dry eye. Eye inserts that act like artificial tears can be inserted in the lower lid. These dissolve slowly releasing moisture into the eye throughout the day. Medication to reduce inflammation or to stimulate tear production may be prescribed. Scleral or bandage contact lenses which trap moisture and prevent it from evaporating too quickly may be an option in cases of more severe dry eye. Procedures that may be helpful include partially or completely closing the tear ducts to reduce tear loss, or silicone plugs to block the tear ducts. If there is an underlying health issue or side effects from medication is causing the problem, managing these can help relieve the symptoms of dry eye.
In recent years new treatment options are being researched offering a new perspective on the dry eye condition. The latest research is focused on the development of new biological strategies, with the goals of preventing disease progression, regenerating affected tissues and maintaining corneal transparency. Use of the patient's own antibodies and growth factors, as well as umbilical cord blood serum have been found to be effective although they are generally costly. There is increasing interest in stem cell therapy to treat a number of conditions including diseases of the eyes. Due to the complexity of cell-based therapies, there is no cure for dry eye yet, but research is ongoing and researchers are hopeful of a cure.
One new treatment generates an intense regulated pulse light which stimulates the meibomian glands and is claimed to return their normal function. Treatment sessions are short and painless and appear to have a high success rate. The treatment is cumulative and therefore needs to be repeated 3-4 times over the course of 1-2 months to maintain the improvement. The results usually last for 1 week after the first session, 2-3 weeks following the second session and 2 months to 2 years after 3 or 4 sessions.
Home remedies to relieve discomfort and soothe the eyes include warm compresses or eye masks. If eye drops are being used, be sure to maintain lubrication by using them even if your eyes feel fine. The inclusion of omega-3 fatty acids either in the diet or as supplements may help the symptoms of dry eye by reducing inflammation in the body. Use a humidifier to increase the moisture in the air. Keep the body hydrated by drinking adequate amounts of water throughout the day. Most importantly, remember to blink to keep the eyes lubricated. When we are concentrating on something like computer work or reading a book, we tend to blink less often, and our eyes tend to become dry – be aware of blinking regularly!
BE SUN SMART
Thanks to widespread publicity on the damaging effects of ultraviolet light on the skin, most people are aware of this issue and responsible about protecting their skin and the skin of their children. Less attention is paid to protecting the eyes from the sun, particularly in children. Children receive more annual sun exposure than adults because many of their activities take place outdoors increasing their exposure to damaging ultraviolet (UV) light. Because children's eyes are not yet fully developed, they cannot filter UV light and prevent it from reaching their retinas as effectively as adults can, with the result that they are more susceptible to retinal damage.
Excessive exposure to UV light can lead to both short-term and long-term eye problems. In the short-term, exposure can result in bloodshot, swollen eyes and a hyper-sensitivity to light. Over a lifetime, damage from unprotected exposure to UV rays can lead to eye conditions that will affect the health of the eyes and vision. Unlike the short-term problems caused by UV rays, the long-term damage caused by repeated overexposure will not fade as the symptoms and conditions caused by repeated overexposure appear over a longer period of time. Because UV exposure is cumulative, it is important to begin protecting the eyes from a young age.
The solution for protecting children's eyes from UV exposure seems to be a simple one. Sunglasses! However, it is a little more complicated than this. When should children start wearing sunglasses? How do we select sunglasses that offer sufficient protection? How can children be encouraged to wear their sunglasses? How can we prevent them being lost? Children generally wear hats when they are outdoors; do they not offer protection to the eyes?
According to some experts, children should start wearing sunglasses from the age of three years. It may be difficult at first but should get easier as it becomes a habit like sunscreen and a hat. Sunglasses should be worn on overcast as well as sunny days as the sun's rays penetrate the clouds all year round. To ensure that there is full UV protection, choose sunglasses that offer 100% of UVA and UVB protection and be sure that this is stated on the label. Some labels simply say “Blocks UV rays”! Polarised lenses can help protect the eyes by reducing glare but they do not offer UV protection on their own so need to be combined with UV blocking. If the child wears prescription glasses, she will either need a second tinted pair of glasses, which can be costly, or to avoid needing two pairs, glasses with photochromic lenses that change from light to dark are an option. Discuss this with your optometrist.
Polycarbonate lenses are ideal for children – they are impact-resistant and lighter than standard lenses, and polycarbonate itself is UV protective. A large frame always provides the best protection, with temples that are a little wider to prevent peripheral sun from getting in. The frame should be close-fitting and flexible so that it is less likely to break. Most importantly, it should feel comfortable.
When shopping for sunglasses, shop at a credible source. Within certain parameters, let the child choose the style, making it more likely that he will wear and take care of the sunglasses. If he or she is resistant, point out role models who wear sunglasses, like sporting heroes or TV celebrities. Remember that price is not necessarily an indicator of quality, more expensive does not mean more effective. Be guided by your optometrist. Lead by example, modeling the habit of regularly wearing sunglasses and taking care of them.
Some sunshine is necessary for our bodies to process vitamin D, but over-exposure to the sun's rays can be harmful. While wearing a wide-brimmed hat or playing in the shade may reduce UV exposure, UV rays reflect off a variety of surfaces and affect the eyes. A hat is not a substitute for the protection offered by wearing sunglasses.
WHEN YOUR BRAIN CAN'T BELIEVE YOUR EYES!
Everything that enters the senses needs to be interpreted through the brain - and these interpretations occasionally go wrong. Optical illusions occur when our eyes send information to our brains that tricks us into perceiving something that does not match reality. There is a mismatch between our subjective perception and the physical reality of what we are observing. Although called “optical illusions” this is not entirely accurate because they have more to do with how the brain processes information than with the way the eyes take it in. An illusion is proof that we don't always see what we think we do because of the way the brain and entire visual system perceive and interpret an image. Illusions are more than parlour tricks; they are important tools that can offer scientists new insights on how vision and the brain work.
Optical illusions have been around a long time and are everywhere, even in nature. Centuries ago in ancient Greece, Aristotle noted that when he looked at a waterfall and then shifted his gaze to static rocks nearby, it appeared as though the rocks were moving in the opposite direction to the waterfall. The Op-Art movement in the 1960s and 1970s showcased a whole new series of illusions as fine art, using classic notions of apparent motion, twists of perspective and the visual influence of adjacent objects.
Not all illusions work the same way, and we are deceived by illusions for various reasons. Colour, motion, shape, perspective and the amount of light that enters the eye are just a few of the factors that might cause us to see an illusion. Sometimes illusions work because of shortcomings in the normal anatomy of our eyes. The brain, too, is guilty of causing us to be fooled by what we see. It can sometimes be too quick to make assumptions about how the world should be instead of how the world actually is, causing us to see things incorrectly.
|With this puzzle, do we notice the colour or its name?|
|The Mach band illusion is an example of a physiological illusion, an illusion caused by a physiological property in the eye. The line in the middle of the picture is one solid color. However, because of how the eye's retina filters the different shades on either side of the line, the right side of the line appears darker, while the left side of the line appears lighter.|
|Cognitive illusions, such as ambiguous, distorting and paradox illusions, occur when our brains automatically make assumptions based on the information sent from the eyes.
Ambiguous illusions are pictures or objects that can be seen in more than one way. Can you see a duck and a rabbit?
|Distorting illusions use different techniques to make objects of similar size, length or curvature appear distorted.|
|Paradox illusions occur as a result of pictures or objects that cannot exist or are physically impossible. Paradox illusions are popular in works of art and photography, which trick our eyes and brains into seeing what is not really there.|
|In this illusion of perspective, when viewed from one angle these are simply metal poles of different shapes, while from another angle they are seen as a portrait of Nelson Mandela.|
According to some experts, optical illusions can help to make our brains sharper. They make us think about how a certain thing may be possible and lead us to understand the working of the human brain. They help in understanding the actual difference between 'looking' and 'seeing', between simply observing and observing with the intention of finding meaning and understanding.
Optical illusions provide us with food for thought, which intensifies and heightens the thinking process. It can help children to develop their cognitive abilities. Some health experts report that optical illusions can help with sharpening memory, improving problem solving skills, visual recall and spatial reasoning abilities. And they are lots of fun!
HEARING COLOUR, TASTING SOUND
Colour is usually experienced visually via the eyes, and sound is experienced auditorily via the ears. How then is it possible to hear colour and taste sound? Some people have synesthesia, a neurological condition in which the stimulation of one sensory pathway leads to an automatic involuntary experience in another pathway; when one sense is activated another unrelated sense is activated at the same time. For example, when hearing music, patterns of colour are visualised. The exact incidence of synesthesia is not known but it is estimated that 3 to 5 percent of people have some form of it, many of them unaware that what they experience is unusual.
Artist Neil Harbisson was born with an extreme and rare form of colour blindness, achromatopsia, resulting in his inability to see colour at all, except in shades of grey. At the age of 16 he decided to study art because he wanted to understand what colour was.
Although his first tutor had reservations, Neil was allowed to do the entire art course using only black and white. He discovered that throughout history there have been many famous people with synesthesia, many of whom related colour to sound.
His life changed when he had an antenna surgically implanted in his brain, which transforms light waves into sound, enabling him to feel and hear colours as audible vibrations. Neil claims he can see 360 colours, including colours invisible to the human eye, such as infrareds and ultraviolets.
It took Neil a few weeks to adapt to his device but once he had he even started dreaming in colour.
SOMEONE ELSE'S EYES
Halloween has never been big in South Africa. The idea of dress-up and candy is an all-American tradition, and we just never caught on. Although, there's something to be said for putting on a mask and disappearing into a character. It's the one night of the year when everybody gets to be somebody else.
So if you could be anybody, who would you be?
Or to put it another way, whose glasses would you wear to see the world through different eyes?
It's been said that politicians have rose-coloured spectacles. So it would be a pleasant experience to put on a pair – you wouldn't see nasty little things like crime and unemployment. From the viewpoint of your government, those things just don't exist... right? (But enough about that...)
Try on the super-stylish titanium frames belonging to a seasoned investor. Maybe you'll see opportunity where others don't. Put on a doctor's glasses and you'll see how to fix people (although you probably won't be able to read your own awful handwriting). An accountant's glasses will show you the world as one giant balance sheet. And a developer's thick lenses (if you'll excuse the stereotype) will reveal the world as a giant matrix of zeros and ones.
If you really want to go deep and philosophical, put on the dirt-stained glasses of a grassroots community changemaker. Maybe you won't see the world as it is, but you'll see it as it should be.
Put on a millennial's oversized retro shades and you might have double vision. From one eye you'll get a cynical view of a broken world, and from the other you'll see an overwhelming exuberance you just can't wait to share on Instagram (if you'll excuse another bit of stereotyping). But don't expect improved vision from a pair of black-framed hipster glasses – you know, the ones generally worn with beards. You might find nothing but window glass inside, because those glasses could be just for show. You know, to be “ironic”. (Once again, stereo... okay, I'll stop apologising.)
And if you want to think bigger, think superheroes. Imagine what a pair of X-ray glasses would reveal. But you've got to ask yourself whether you really want to see everybody's underwear. Not to mention whether you want to see what's going on inside their heads. (Maybe not...)
So this October, don't rush out and buy a witch's hat. Just put on a pair of unfamiliar glasses and see what this planet looks like through somebody else's eyes. You just never know what you might see.