June 2017


AT ARM'S LENGTH

As we get older, we find ourselves holding reading material further and further away. This is not because our arms are getting shorter! Rather, our eyes are losing their ability to focus up close, be it on reading a menu, threading a sewing needle, or tightening a small screw. This is one of the symptoms of presbyopia, the vision condition commonly associated with the aging process, and caused by the gradual loss of flexibility in the lens of the eye. Few people escape presbyopia, even if they have never had a vision problem requiring glasses before.

There are a number of treatment options for presbyopia, including glasses, contact lenses and surgery, and within these options there are various possibilities. Discuss these with your optometrist, who will guide you in terms of your specific needs.

CORRECTIVE LENSES

For those who need glasses for close work, but not for distance vision, the simplest solution is usually reading glasses, which can either be made up by your optometrist or even bought over the counter. Some people prefer to have bifocal (or progressive) reading glasses, with "plano" lenses (no prescription) in the top part of the lens and the reading prescription in the bottom, so that they're able to wear glasses full-time without having to constantly take them on and off.

If both distance and near vision need to be corrected, bifocal or progressive lenses would be the answer. Bifocal lenses have two points of focus, the main part being the prescription for distance vision, while the lower portion is for close work. While bifocal lenses correct only near and distance vision with a clear line between them, progressive lenses work for distance, intermediate and near ranges, with a continuous transition and no clear distinction between the different powers. Although vision is not necessarily better with progressive lenses, the uninterrupted transition from one distance to another is more natural, and they are cosmetically more attractive without the noticeable line. Without the image jump characteristic of bifocals, they are thought to be safer for driving. Some people think of progressive lenses as having three lenses in one, without the expense of three pairs of glasses or the nuisance of changing glasses for different vision needs.

It usually takes time to adjust to wearing bifocal and progressive lenses. During the adjustment period, wear the new glasses as often as possible, avoiding the temptation to go back to your old comfortable single vision glasses, as this can delay the process. Try to point your nose and chin at what you are looking at, whether it's a book, computer or traffic ahead. Lower your eyes rather than your head when reading. Peripheral vision may be distorted with progressive lenses, so turn your head when looking to the side. Allow up to two weeks to adjust, after which time any headaches, dizziness or other problems should be discussed with your optometrist.

CONTACT LENSES

Contact lenses can be a successful option for presbyopia. Like glasses, they are available in bifocal and multifocal alternatives, and are suitable for most prescriptions.

ALTERNATING VISION LENSES work similarly to bifocal glasses, where the top portion of the lens is used for distance viewing, and the lower third for close tasks. Most alternating vision lenses are rigid gas permeable lenses, and are slightly smaller than soft contact lenses. They float on the surface of the eye, resting just above the lower eyelid. When focusing on medium to long distances, the gaze remains level, and the middle to upper part of the lens is used. As the gaze drops for reading or other close activities, the lens remains stationary, and the view is through the lower portion of the lens. The lens can be made in a way that offers a clear, distinct line between the different powers, or there can be a gentle gradient between them that slowly transitions from one power to the other as the gaze drops.

MULTIFOCAL CONTACT LENSES or simultaneous vision lenses are made with different powers in one lens, targeting vision at varying distances, much like the progressive lenses for glasses. They are available in a wide range of styles and designs, with comfortable options for almost everybody. The different focal strengths are either arranged in concentric circles, from the centre of the eye outwards, or by a gentle gradient as the powers blend between near and distant vision.

Many people feel that multifocal contact lenses offer the best of both worlds - sharp clear vision without the need for glasses. However, as with most things, they do have disadvantages. Some people find it difficult adjusting both to wearing contact lenses and to the new vision experience. During the initial adjustment period and sometimes even longer, night time glare, shadows and starbursts poses a problem for some wearers.

MONOVISION is a variation on the standard use of contact lenses to help people with presbyopia. Even though most people have binocular vision, with the eyes working together, one eye is usually dominant over the other. With monovision, the dominant eye is fitted with a contact lens for distance vision, while the non-dominant eye is fitted with a lens for close work. The result is a compromise between distance and close-up vision. Overall, people who use monovision tend to adapt easily and see both distance and close-up items reasonably well, although some people find that their vision is not sharp enough for either. Generally, a certain amount of depth perception is lost, and some people experience difficulty with driving, particularly at night with the glare of oncoming headlights. A discussion with your optometrist will explore this as a choice for your lifestyle and vision needs.

SURGERY

The effects of monovision can be achieved with LASIK surgery, and is often the choice of people who prefer not to wear glasses or contact lenses. Using a laser, an ophthalmologist reshapes the cornea (the clear membrane in front of the eye) for distance vision in one eye and close vision in the other. The procedure is painless, healing takes place quickly, and improvement in vision is experienced almost immediately. Some people complain of compromised night vision after LASIK. It has been suggested that patients try monovision contact lenses before deciding on surgery, to ascertain that monovision is their best vision option.

No matter which option you choose, presbyopia does progress over time, and your contact lens or glasses prescription may increase to keep up with it. Regular eye examinations and consultations with your optometrist will ensure that your prescription is always up to date and providing you with the best vision possible.


DOUBLE VISION

When we look at an object and see a single clear image, we give no thought to the different areas of the visual system that need to work together to allow us to see this image. Light enters the cornea, the clear membrane over the front of the eye, and the lens helps to focus the light onto the retina at the back of the eye, from where information is carried via the optic nerve to the brain. The muscles of the eye move the eye in different directions. A problem with any part of this delicate system can lead to double vision or diplopia, the perception of two images of a single object. The images can be side by side, one above the other, or a combination of the two; they may overlap or appear as two separate images. Double vision can affect just one eye (monocular) or both eyes (binocular). As well as the obvious difficulties of navigating the world while viewing a double image, double vision can also cause disruptions in balance, movement and reading ability.

CAUSES OF DOUBLE VISION

Double vision occurs when the eyes are unable to look in the same direction. There are a number of possible causes for this, some relatively minor and others more serious, some of which originate in the eyes, while others may be symptoms of underlying conditions within the body.

Monocular double vision is less common than binocular double vision and can be caused by conditions within the eye itself, which distort the transmission of light through the eye to the retina. These include problems with the shape of the cornea, an abnormality of the lens or retina, or an injury to the eye causing blood and fluid to build up around the eye and press on the nerves and muscles around it.

The control of eye movement depends on three sets of eye muscles working together with each other and with the brain. If damage occurs to the muscles or nerves that control eye movement, a double image may result. Anything that mechanically interferes with eye movement can prevent the eyes from aligning properly, and cause double vision. Most commonly, the eyes are misaligned because of a disorder affecting the nerves supplying the muscles that move the eyes. Sometimes the cause is unknown, however known causes include disorders that typically interfere with the ability of the nerves to control muscles throughout the body, including the muscles of the eyes. Examples of these are certain thyroid problems, stroke, diabetes, aneurysm, multiple sclerosis, brain tumour, myasthenia gravis, and head injury.

The question is sometimes asked if a squint is the same as double vision. Although a squint may cause double vision, it is not the same condition. A squint occurs when the eyes are not perfectly aligned and are looking in two different directions. Depending on the cause of the squint, it may not always lead to double vision. Factors that may cause a squint include paralysed or weak eye muscles, unbalanced eye muscles, or ineffective nerve control of the eye muscles. If a person has had a squint from childhood, he or she is unlikely to experience double vision because the brain learned at an early age to ignore the double image, using one eye at a time to view an image. If the squint is acquired in adulthood, the brain is unable to learn to ignore the double image, resulting in double vision.

Temporary double vision may be the result of certain drugs, concussion, alcohol intoxication, or extreme fatigue or eye strain. If normal vision does not return within a reasonable period of time, professional intervention may be needed.

DIAGNOSING DOUBLE VISION

Because of the large number of possible causes, diagnosing double vision can be challenging. Questions that may be asked include whether the double vision is in one or both eyes, if it is constant or comes and goes, and if it occurs only when the person is looking in a particular direction. Further questions are if there is pain, numbness, weakness of facial muscles, dizziness, and speech or swallowing difficulties, or a recent eye or head injury, any of which may be a cause for concern that the double vision may represent problems with the nervous system.

The eye examination aims to investigate bulging of one or both eyes, drooping eyelids, the pupil's response to light, and an assessment of the internal structures of the eyes under magnification.

Some cases of double vision clear up without treatment. If symptoms and examination findings suggest no serious cause, the optometrist may recommend that your eyes be checked regularly for a few weeks to see whether the vision clears up. If necessary, he may refer you for further testing.

Because children are unaware that they may be seeing differently from others and cannot express what they are perceiving, diagnosing double vision in children can be more difficult. Signs to watch out for include squinting or narrowing the eyes, covering one eye with the hand, turning the head to view an object, or looking at objects from the side rather than facing forward.

TREATMENT OF DOUBLE VISION

Double vision can be quite debilitating and uncomfortable to live with, but it will not harm your eyes or your brain. Some of the conditions that cause double vision, however, can be harmful to the eyes and even to general health, so should be treated as early as possible. The treatment for double vision varies, depending on the underlying cause. If it is related to a medical condition, it should be managed by a medical professional.

As a short-term solution, immediate relief from the discomfort of double vision can be achieved by covering one eye. Your optometrist can advise on the best way to treat double vision and may recommend specific eye exercises to strengthen weak eye muscles or even glasses with prism lenses, a wedge-shaped piece of glass or plastic which diverts the light rays to the angle at which the eye is looking. This allows the person to see singly without moving the position of the eyes.

Occasionally Botox, a drug that paralyses muscles, may be injected into one of the extraocular muscles. By paralysing one of the muscles the balance of muscle power is re-established, and the other extraocular muscles can pull the eye into the correct position. This treatment lasts for approximately 12 weeks and then needs to be repeated.

In certain cases, surgical correction may be required to correct a squint. The operation involves strengthening or weakening certain extraocular muscles, so that the balance of muscle power is corrected and the eye is pulled into the correct position. If a muscle is not working effectively, it may be shortened by cutting out a piece of the muscle.

Some squints will resolve without any treatment and so the double vision resolves with it. This is particularly true for double vision due to stroke; in the majority of cases the squint will disappear after three to six months.

Double vision should always be evaluated by a professional, even if it is temporary. People who have warning signs and symptoms other than double vision should be evaluated by a doctor immediately. All people who have double vision, even if it has resolved, should see an optometrist within a few days, and continue to have regular check-ups.


A DIFFERENT WAY OF LOOKING AT LIFE

"Whatever hand life deals you, you don't have to give in to it. You just need to find a different way of... looking at it!" These wise words sum up the attitude of a man who is used to falling down, picking himself up again, and carrying on, a man used to "looking" at life differently!

Richard Monisi was born blind, regaining 5% of his sight after an operation at the age of 12. Forced to drop out of school early, he moved from his rural village to Johannesburg where he discovered long distance running. It was difficult to find time to train, so Richard chose to train in the quiet early hours of the morning, so that he could concentrate on his senses other than sight to guide him through the streets, before the confusing noise of the day began.

He has since finished 11 Two Oceans marathons, and is preparing to run his 12th Comrades Marathon on 4th June 2017. During one of his races, he fell four times, picking himself up each time and continuing towards the finish line. As he entered the stadium, he was disoriented by the music and cheering crowds. He lost his balance and fell, but was lifted to his feet by nearby runners, who urged him not to give up, to keep going to the end, something he has been doing throughout his life.

In 2013, his guide collapsed due to dehydration, but Richard would not give up - he made sure that his guide was taken care of, took out his white cane and finished the race, spurred on by his own determination and the encouragement of his fellow runners. For Richard, the start of the Comrades Marathon is a difficult experience - it scares him. He can hear lots of people all talking at the same time, lots of people making nervous noise. The loud music adds to his trepidation. For the first few kilometers, surrounded by many runners, Richard struggles to set his pace, but as the crowd thins, he gets into his stride. He tracks the time by the sun, feeling its warmth and shadow on his face at different times of the day. Unable to see the distance markers, Richard relies on the camaraderie of the other runners.

"We're halfway!" shouts a fellow runner. Recognising his voice, Richard's heart lightens - he remembers that they run at the same pace and realises he is on track for a good finishing time.

This brave man who can't see can teach us a lot about the way we look at the world.


MILLENNIALS: A GUEST ARTICLE BY A FUNKY YOUNG PAIR OF GLASSES

The Youth. Those Millennials. What Is The World Coming To? Sound familiar? It should... I mean, you guys just don't stop complaining about us. It's always young people this and young people that. For reals, it never ends.

Well, you know what? It's Youth Month and I've got some stuff to say. Yip, this is a real Millennial talking.

Let's start with the complaint that we can't focus on one task. That's what we call multitasking. (Hello, like obviously...) As we speak I'm polishing my lenses and checking my messages while I'm writing this article. Then people say we don't do anything thoroughly. Well how thoroughly do you want me to check my Facebook status? Thoroughly, really? Whatevs.

Then there are those peeps who say we only care about ourselves. Seriously? Look at all the protests around the world. You know, the ones in favour of human rights and the ones against a certain orange president. Who was doing most of the protesting?

As a young funky pair of sunglasses, I've been worn to many places where young voices demanded to be heard. So you see? We do care about the world around us. One time I got left behind which was totes awks (meaning totally awkward, in case you don't speak our lingo).

Ah yes, our lingo...

So. People say we're obsessed with FOMO, which by the way means Fear of Missing Out. Sure, we want to do stuff and experience life. But sometimes there's JOMO (which is Joy of Missing Out, like when you see people out doing stuff but you're happy to be at home on the couch). FOMO is almost the same as YOLO, which is You Only Live Once.

We want to make the most of life. But nobody wants to do it alone like some rando (random person... are you getting the hang of this?)

So FOMO and YOLO are almost the same, but sometimes there's JOMO and that's okay too. But you don't want people to think you're a rando. Got it? See, it all makes sense.

We get a hard time from people who think we act like the world belongs to us. Well one day it will, so maybe we all need to start getting used to the idea. And so what if it's a world full of selfies and status updates? It'll also be a world of people speaking out for their rights and planting trees... because yes, we do that a lot.

Anyway, one day we'll have our own kids and we'll complain about them as much as people complain about us. Circle of life and all of that.

And that whole deal about how we have no attention span? Well I just wrote 475 words, didn't I?