EyeMark Newsletters

A list of all our EyeMark Newsletter Articles

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EYES FRONT!


Strabismus A squint, or strabismus, is a condition in which the eyes do not work together to look in the same direction at the same time.Whilst one eye may look straight ahead, the other eye points outwards, inwards, upwards or downwards. HOW DO THE EYE MUSCLES WORK? The movement of each eye is controlled by muscles that pull the eye in specific directions, outwards, inwards, upwards and downwards. Additional sets of muscles help to stabilise the eye movements, particularly for looking downwards and inwards, or for upward and outward movements. With normal binocular vision, both eyes look and focus on the same spot. The brain combines the signals from the two eyes to form a three-dimensional image. A squint develops when the eye muscles do not move together in a balanced way, the two eyes focus on different spots, and the brain receives two different images. In some cases of squint, the eyes will take turns to focus, resulting in an alternating squint. As both eyes are doing some focusing, the visual pathways to the brain develop from both eyes. However, in many cases of squint, one eye will remain the dominant, focusing eye. The weaker (squinting) eye is not used to focus, and the brain ignores the signals from this eye, in order to avoid double vision. This lack of use means that the non-dominant eye fails to develop the normal visual pathways in childhood and visual loss, or amblyopia, develops. The child effectively only sees with one eye, resulting...
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WORLD RETINA WEEK: 21 to 27 September


A Cure is in Sight for Retinal Blindness - trust science! World Retina Week is observed in over 40 countries to create awareness of the progress towards treatment for retinal genetic conditions through scientific research. The remarkable progress being made in the fields of Gene Therapy, Stem cells and Artificial Retinas makes the dream of treatment for as yet incurable blindness an exciting reality. Retinal conditions such as Macular Degenerations and Dystrophies, Retinitis Pigmentosa, and other rare conditions cause loss of vision in over 40 million people worldwide and a probable 150 000 South Africans. Clinical trials to find effective treatments are showing great promise and Retina South Africa is determined to bring these promising trials to South Africa. Early diagnosis is essential and Retina South Africa is appealing to all Optometrists to be aware of the early symptoms and ensure that their patients receive the correct advice and diagnosis. Many patients affected by the Retinitis Pigmentosa group of conditions may have good visual acuity but poor night and contrast vision and slow adaptation times. Children with cone dystrophies are often extremely photophobic (sensitive to light). As all these conditions vary considerably in age of onset and severity a brief patient history may prove to be of great benefit. Here is a list of questions you can consider asking your patients: Do you regularly: Collide with obstacles or people Feel insecure in dark or dimly lit and unfamiliar areas Experience problems going up or down stairs Become disorientated in brightly lit...
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EYE HEALTH IS EVERYONE'S BUSINESS


September 21st until October 18th is Eye Care Awareness Month. This South African initiative is aimed at creating national awareness around the importance of eye health. 80% of blindness is avoidable and the message that blindness can be prevented is central to this initiative. Prevention and treatment of avoidable blindness are core focus areas. Activities during Eye Care Awareness Month every year revolve around an intensified drive to try and reduce the backlog in cataract surgeries in the country. The Bureau for the Prevention of Blindness perform "cataract blitzes". This means that the different teams, or mobile eye care units, of the Bureau, coordinate and conduct a high volume of cataract surgeries in under-serviced, rural communities all over the country throughout October. This is done in partnership with the different Provincial Departments of Health. Each year a different theme is chosen to raise awareness of eye health. The theme this year is "Eye Health is Everyone's Business", referring to the fact that eye care should be a priority for all sectors, institutions and individuals who are responsible for decision-making regarding healthcare. The message to all South Africans for Eye Care Awareness Month is: Have your eyes tested this month, wear sunglasses and protect your eyes against injuries. 80% of blindness is avoidable, take the necessary precautions and don't become a statistic.
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WHY RABBITS DON'T NEED GLASSES!


Myths Around Vision If you cross your eyes and the wind changes, you will remain squint forever. Crying excessively will damage your eyes, as will excessive reading. If you try on some-one else's glasses you will weaken your eyes. Leaving a night light on in your baby's room will lead to visual problems later in life. Old wives' tales? Scare tactics used by parents (or grandparents) to discipline their children? While some of these are clearly untrue, some of the ideas around vision stem from sound truth. 1. Eating Carrots Will Improve Your Vision FACT: Diet is important for good vision, and carrots are high in vitamin A, an essential nutrient for good vision. However, carrots are not the only source of vitamin A which is also found in milk, cheese, egg yolk and liver. Dark green leafy vegetables, which contain lutein, may play a role in preventing macular degeneration, and fresh fruit is a good source of antioxidant vitamins C and E, which can help protect the eyes from cataracts. Vitamins will not prevent visual conditions such as shortsightedness or farsightedness. 2. Sitting Too Close to the TV Will Damage Your Vision LARGELY MYTH: Sitting closer than necessary to the television may give you a headache, but there is no evidence to suggest that it will harm your eyes. Long hours in front of the TV or computer screen may cause eye strain or computer vision syndrome, but there are techniques you can use to relieve this, for example being...
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QUALITY COUNTS!


ON THE LIGHTER SIDE! "How's this for good quality spectacles?" asks an optometrist in Tzaneen. These spectacles were lost in the Tzaneen dam 13 months ago. When our patient returned to the same spot 13 months later, the water level in the dam had fallen, and there were his spectacles. As you can see in the photo, they were caked in mud and looking very sad! We cleaned them, and imagine our surprise when the frame still functioned perfectly although it had lost a little of its "gold"! The lenses were slightly scratched at the bottom, but were completely intact. He now has a spare pair of spectacles - courtesy of the Tzaneen dam!!
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SHEDDING LIGHT ON NIGHT BLINDNESS


"Night blindness" or nyctalopia is not true blindness, and the term more accurately describes the inability or reduced ability to see in dim light or darkness, or refers to the prolonged time it takes for the eyes to adapt in dark conditions. How we see Light rays travel through the cornea and the lens to the retina at the back of the eye. The retina is composed of photoreceptors, which are specialised nerve cells that receive light rays and convert them into electrical signals, which are then transmitted to the brain, creating an image. There are two types of photoreceptors, rods and cones. Among other functions, rods are responsible for vision in dim light, while cones are responsible for vision in bright light. Another important function of rods is to adapt to darkness, for example walking indoors after being in sunlight. The two types of photoreceptors are similar in structure, but while pigments in cones can distinguish between wavelengths of colour, rods only see black and white. Symptoms of Night Blindness Symptoms vary for each patient, and may include weak vision in dim light, difficulty seeing during night driving, and slow vision adaption between bright and dim light conditions. Causes & Related Conditions Night blindness itself is not serious, and is often a symptom of other conditions. Cataracts - As the lens of the eye becomes gradually clouded, vision is reduced. As well as reduced night vision, halos may be experienced around lights at night. Genetic Eye Disease - Examples include...
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NOT QUITE IN THE PINK!


Struggling to open your eyes because they are sore, gritty, red, sensitive to light and have a yellowish discharge? Chances are you have conjunctivitis, or "pinkeye", as it is commonly known. Conjunctivitis is an inflammation or infection of the conjunctiva, the thin transparent membrane that lines the inner surface of the eyelid and covers the white part of the eye. It is a common eye condition, and can occur in people of all ages. Infectious conjunctivitis is more common in children than adults as bacteria and viruses are easily spread by children when they play.It may affect one or both eyes. What causes conjunctivitis? There are various types of conjunctivitis, with differing causes. Allergic Conjunctivitis is non-infectious, and occurs most commonly in people who have seasonal allergies. It is caused by allergens such as pollens and dust, and is often associated with hayfever. Environmental or chemical forms of conjunctivitis are caused by irritating substances entering the eyes, for example household cleaners, smoke, foreign objects, smog, swimming pool chemicals and industrial pollutants. Giant Papillary Conjunctivitis is a type of allergic conjunctivitis caused by the chronic presence of a foreign body in the eye. It may occur with people who wear hard contact lenses, wear soft contact lenses that are not replaced frequently, or have an exposed suture on the surface of the eye. Bacterial Conjunctivitis is an infection caused by a bacteria, sometimes from one's own skin or respiratory system. Infection can also occur by physical contact with other people, touching the...
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TASTING THE LIGHT


A device that lets the Blind "See" with Their Tongues Neuroscientist Paul Bach-y-Rita hypothesised in the 1960s that, "We see with our brains not our eyes." Now, a new device trades on that thinking and aims to partially restore the experience of vision for the blind and visually impaired, by relying on the nerves on the tongue's surface to send light signals to the brain via a different pathway. With BrainPort, the device being developed by neuroscientists in the USA, visual data are collected through a small digital video camera about 1.5 centimetres in diameter that sits in the centre of a pair of sunglasses worn by the user. Bypassing the eyes, the data are transmitted to a handheld base unit, which is a little larger than a cell phone. This unit converts the digital signal into electrical pulses, replacing the function of the retina. From the CPU, the signals are sent to the tongue via a "lollipop," an electrode array about nine square centimetres that sits directly on the tongue. Densely packed nerves on the tongue surface receive the incoming electrical signals, which feel a little like champagne bubbles. Within 15 minutes of using the device, blind people can begin interpreting spatial information via the BrainPort. "It becomes a task of learning," Arnoldussen, one of the researches, says, adding that the "process is similar to how a baby learns to see. Things may be strange at first, but over time they become familiar." Seiple, another one of the researchers, works...
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DON’T LOSE SIGHT OF CLOUDY VISION!


What is a cataract? A cataract is a clouding of the normally clear lens in the eye. For people who have cataracts, seeing through a cloudy lens is like looking through a fogged-up window. Cataracts are very common in older people. What does the lens do? The lens functions much like a camera, focusing light that enters the eye onto the retina at the back of the eye. Once it reaches the retina, light is changed into nerve signals that are sent via the optic nerve to the brain. The lens must be clear for the retina to receive a sharp image. How do cataracts form? As we age, the lens in the eyes becomes less flexible, less transparent and thicker. Tissues within the lens break down and clump together, clouding small areas within the lens. As the cataract continues to develop, the clouding becomes denser and involves a greater part of the lens, which begins to discolour to yellowish/brown. The cataract scatters the light as it passes through the lens, preventing a sharp image from reaching the retina, and resulting in blurred vision. Cataracts may develop in only one eye, but they usually develop in both eyes, although they may not be totally symmetrical, and the cataract may be more advanced in one eye. How do cataracts affect vision? Most age-related cataracts develop gradually, so changes in vision may not be noticed at first. As the cataract grows larger and clouds more of the lens, you may become aware of...
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A GOOD CRY CAN BE GOOD FOR YOUR EYES!


Tears have numerous functions – they are the emotional response to certain situations, a reflex response to strong fragrances or fumes, but most importantly, they maintain clear vision and comfort by providing moisture and lubrication to the eyes. With each blink of the eyelids, tears are spread across the front surface of the eye, known as the cornea. Tears are made up of water for moisture, oils for lubrication, mucous for even spreading, and antibodies and special proteins for resistance to infection. Each of these components is produced by different glands within the eyes. Excess tears in the eyes flow into small drainage ducts in the inner corners of the eyelids, which drain in the back of the nose. Dry eye is a condition in which there are insufficient tears, the tears are of a poor quality, or there is an improper balance between tear production and drainage. Dry eye is a common and often chronic problem, particularly in older adults. Symptoms of Dry Eyes Dry eye symptoms may appear suddenly or gradually, and can last for hours or days. They may range from mildly irritating to extremely uncomfortable. Common dry eye symptoms include discomfort or eye pain, light sensitivity, a gritty sensation in the eye, redness, swollen eyes, eye fatigue, itchy eyes, blurring of vision and eyelid twitching. Sometimes, a person with dry eyes will have excess tears, which may seem confusing. This happens when the eye isn't getting enough lubrication, and sends a distress signal through the nervous system...
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