EyeMark Newsletters

Does a camera record the same kind of images as our eyes do? We assume that it does, but the camera and the eye ‘see’ differently. The camera is more reliable than the eye, because it records what is actually out there. The eye, on the other hand, ‘chooses’ what it wants to see – it highlights the object of greatest interest, often not even registering other objects in the picture. The eye sees what it hopes and expects to see, based on our previous experience and knowledge of the world around us. The answer, then, is that the camera doesn’t lie, but our eyes do!

Shiny shoes, smart uniform, brand new suitcase packed with learning materials, all the outward signs of your child’s readiness for school when the new year begins. But, is he ready to cope with the demands of school and start the formal learning process? A child’s readiness for school encompasses a range of skills which develop during the critical first five years of his life, long before school starts. He needs to be prepared physically, socially, emotionally, and have good cognitive, language and perceptual abilities, in order to achieve and thrive in the school environment. Readiness is not a static state in the child’s development, but is an ongoing process, which is enhanced by the support and stimulation of the people in the child’s world. On a physical level, the child should be able to perform a variety of gross motor tasks, such as climbing, skipping and catching a ball, with confidence. His fine motor abilities should include cutting with scissors, drawing and being able to use cutlery while eating. Both gross and fine motor abilities are dependent on hand-eye co-ordination. The child’s social and emotional development is the foundation for cognitive development. Can he adapt easily to new social situations? Can he complete tasks on his own without constantly seeking adult assistance? How does he interact with others, both adults and children? Is he confident and self-assured? Does he show responsibility? Can he solve problems and cope with emotional situations in a mature manner for his age? A child’s school performance...

Sunglasses have become a highly sought after and noticeable accessory, making a fashion statement in almost every walk of life. But, let us not forget that the primary purpose of wearing sunglasses is to protect the delicate tissues of the eyes from the harmful rays of the sun. While the sun is a source of light and warmth, and supports life on our planet, we need to be aware that its rays can be damaging. The sun’s primary danger is in the form of ultraviolet (UV) radiation. There are three types of ultraviolet radiation. UV-C is absorbed by the ozone layer and whilst the ozone layer remains intact, does not pose a threat to us. Both UV-B and UV-A can have long-term damaging effects on the skin and the eyes. Even on a cloudy day, there is a danger of UV exposure. UV radiation can also be given off artificially, for example by welding machines and tanning beds. Exposure to small amounts of UV radiation over a period of many years increases the risk of developing cataracts and may cause damage to the retina. The longer the eyes are exposed to UV radiation, the greater the risk of these visual conditions developing later in life. Since it is not clear how much exposure will cause damage, it is recommended that whenever we spend time outdoors we should wear a good pair of sunglasses as well as a cap or hat. What is a GOOD pair of sunglasses? Expensive sometimes means better,...

An elephant in an Amsterdam zoo is the first elephant in Europe to be fitted with a contact lens, after her eye was injured during a scuffle with another elephant. Forty-five year-old elephant Win Thida’s eye began streaming and she was having trouble keeping it open because of the pain. A vet was called in, and an examination revealed that the elephant’s cornea had been damaged. The vet says she has often fitted horses with contact lenses, but this was the first time she attempted the procedure with an elephant. Fortunately, Win Thida was very cooperative. Elephants can’t lie down for long before their immense weight hampers their breathing, so she had to remain standing under anaesthetic, and the vet needed to stand on a ladder to reach her patient’s eye. The treatment took less than an hour, and Win Thida seemed happier immediately after surgery. Protected by the contact lens, the wound on her cornea will now be able to heal, the vet says.

“I see trees of green, Red roses, too. I see them bloom, For me and you! And I think to myself: What a wonderful world!” We all live in a world where colour affects us in our daily lives. Colour in everyday life is very diverse, from knowing that a fruit is ripe to eat, to understanding how colour can affect our moods. What is colour? Colour is simply light of different wavelengths and frequencies. Imagine light travelling in waves like those in the ocean. It is these waves that have the properties of wavelength and frequency. Each colour has its own unique wavelength and frequency. For example, the colour red has a much longer wavelength than the colour violet, so each violet wave would span a much shorter distance. How do we see colour? The retinas in our eyes have three types of colour receptors in the form of cones. Although there are seven main colours on the visible spectrum, we can actually only detect three of them. These visible colours are red, blue and green, and these three colours are mixed in our brain to create all of the other colours we see. Where does colour come from? Colour simply comes from light, sunlight being the main source of colour. Using a prism, we can 'extract' the colours from white light – i.e. sunlight. When light from the sun passes through a prism, the light is split into the seven visible colours by a process called 'refraction'. When we...

Double vision or diplopia is the perception of two images of a single object. Looking at something and seeing a single clear image is something we take for granted, giving no thought to the different areas of the visual system that need to work together to allow us to see this image. The cornea, the clear membrane over the front of the eye, focuses most of the light entering the eye. The lens helps to focus light onto the retina at the back of the eye. The muscles of the eye move the eye in different directions. Nerves carry information from the eyes to the brain. A problem with any part of this delicate system can lead to double vision. Double vision can be monocular, affecting one eye only, or binocular, occurring in both eyes. Causes of Double Vision Problems with the cornea that can cause double vision include infections which can distort the cornea, and scarring or dryness of the cornea. This usually affects one eye only. Cataracts are the most common problem with the lens that can cause double vision. If cataracts are present in both eyes, images from both eyes will be distorted. If the eye muscles are weak, for whatever reason, they cannot control the movement of the eyes effectively, and double vision is experienced. This muscle weakness can occur in one eye or in both eyes, and can be part of a general health condition. There are various conditions that may damage the nerves that control...

Helen Keller – was blind and deaf from the age of 19 months Stevie Wonder – blind from infancy, started recording music at the age of 12 Claude Monet – French Impressionist painter still painted as his vision deteriorated, was thought to have painted his famous ‘Water Lilies’ when he was almost blind Judge Jacoob – South African Constitutional Court judge Erik Weihenmayer – first blind person to summit Mount Everest Andrea Bocelli – opera singer, blind from the age of 12 Louis Braille – went blind at age 3, invented Braille alphabet Ray Charles – musician Zohar Sharon – pro golfer Rafael Arias – Spanish painter Apl.de.ap – Black Eyed Peas rapper Joaquin Rodrigo – composer and guitarist Tofiri Kibuuka – successfully reached the summit of Mount Kilimanjaro Joseph Pulitzer – originator of the Pulitzer Prize Sue Townsend – writer of Adrian Mole series, went blind gradually Steven Kekana – South African musician, and lecturer in Labour Law

Anyone who has been into an optometrist’s practice is familiar with, and has probably experienced, the chart with the ‘big E’, which has become synonymous with vision and visual assessment. This is the Snellen chart, which was produced in 1862 by a Dutch ophthalmologist, Dr Herman Snellen, at a time when visual acuity was assessed using whatever reading material was available. Dr Snellen wanted to be able to test his patients against an objective standard which could be repeated over time. To provide a standard, he designed seven rows of stylised letters which were printed progressively smaller as one moved down the chart. There were variations of this, and it took a century for the development of a generally accepted measurement of visual acuity. Today, as one recognises the contribution Snellen made to visual testing, the Snellen chart is universally accepted and used, although there are many variants of it. The traditional Snellen chart is printed with eleven lines of block letters. The first line has one very large letter, which may be one of several letters, for example E, H, or N. All the rows that follow have increasing numbers of letters that progressively decrease in size. Different charts may have a different number of lines and may vary in the size progression. The patient taking the test has one eye covered while he reads aloud the letters of each row, beginning at the top. The smallest row that can be read accurately indicates the visual acuity in that eye....

Are you over 40 years of age? Do you find that you are seeing less clearly close up? Do you have to hold things further away to see them more clearly? Chances are you have presbyopia, an eye condition which affects most people as part of the natural aging process. Although usually seen in adults over the age of 40, the age of onset varies and there are other factors which play a role. Since presbyopia develops with aging, it is possible to have it in conjunction with other eye conditions such as astigmatism or shortsightedness. What causes presbypoia? In the young eye, the lens and tiny muscles surrounding it are flexible, and are able to quickly and easily adapt to both close and distant images. As the eye ages, the lens loses its elasticity, becoming more rigid and less able to change its shape to effectively focus light on the retina. This is a gradual process, which occurs over a number of years but may be noticed fairly suddenly. Are there risk factors other than age? Certain factors may pose a higher risk of you developing presbyopia earlier than normal. These include certain medical conditions such as cardiovascular disease, medication such as diuretics or antidepressants, and trauma or surgery to the eye. Your optometrist will take a detailed medical history to ensure that these or other risk factors are taken into account. What are the signs of presbyopia? The first sign of presbyopia is a decreased ability to read close...

On the lighter side! Glasses? Eyeglasses? Spectacles? What’s the difference? Well, it seems that the answer lies in both the country and the time in which you are living. Historically, eye glasses were eyewear with no side bars or temples, while spectacles had temples. In Italy in the 15th century, spectacles were sold in the markets; the client would try on various pairs and choose the one that seemed to best suit his needs. In America, the term most commonly used is eyeglasses. The word spectacles is regarded as old-fashioned and sometimes even humorous. In some circles in Britain, an eye glass is a small telescope, and eyewear is called glasses or sometimes specs . In South Africa, we use the terms glasses (NOT eyeglasses) and spectacles interchangeably, although sometimes a distinction is made between spectacles (which are fitted with prescription lenses) and glasses (a more general term including sun glasses, reading glasses , etc). Goggles , although strictly speaking refer to protective eyewear, is a term often used in a negative or derogatory sense.