Spring 2013

Welcome to our latest newsletter. In this edition is an article titled Screen Presence all about computers that are so commonplace these days. Life Through a Lens will inform you all about spectacle lenses. Have you ever wondered how what you eat affects your eyes then read You See What You Eat. Have you ever wondered what colour blindness is then read the article Colouring your Judgement.

Screen Presence

Computer use has become so commonplace nowadays that we barely notice it. Millions of people spend their working day viewing a monitor, while most of us rely on our desktops and laptops for leisure, communications, shopping and academic study. However, the human eye was never designed to focus for long periods of time on brightly illuminated, motionless objects, so a little common-sense and pragmatism is required.

The most common monitor-based sight issues include headaches, dry eyes, fatigue and a gradual loss of sharp vision. A good tip for relaxing eye muscles is to take a brief break every 20 minutes. Regular blinking should prevent uncomfortable dryness, but we blink much less when gazing at computer screens, so moistening drops might be a wise purchase.

Ergonomic monitor positioning is another vital component in preventing eye strain. The screen should be two feet away and at normal eye level, without any strong lights behind or beside it. Brightness settings should be reasonably low, with font sizes large enough to read without squinting. Anti-reflective coatings and screen filters can soften harsh strip lights or dazzling sunshine, and LCD/LED monitors are far less reflective than the chunky old cathode-ray units of yesteryear. Always keep screens as clean as possible, because your eyes will rapidly tire of trying to focus through a layer of dust or grime.

Finally, eye examinations are always important and regular check-ups can help to identify possible VDU-related issues and keep your eyes in good condition to cope with the demands of today’s screen work.

Life through a Lens

Spectacles are an integral component of daily life for many people. While contact lenses are an increasingly popular and user-friendly alternative, the simplicity and convenience of spectacles ensures they’re still the default option for vision correction.

Lens technology has evolved greatly in recent years and it’s now easy to buy spectacles that can block UV light, or prevent the build-up of grease and dirt with oil-resistant films. Much of this sophistication involves transparent chemical coatings applied to the lens and performing specialised duties such as preventing reflections. This concept was developed from the late 19th century onwards, with a major breakthrough occurring in the 1930s when scientists began combining thin layers of film that refract light at different angles, virtually eliminating reflectiveness.

The attendant benefits are particularly pertinent today with glare being alleviated from computer screens and mobile devices, while motorists benefit by avoiding dazzle from oncoming vehicles or street lights when travelling at night.

Nowadays, anti-reflective coatings are fairly standard on spectacles, and they are increasingly being augmented by scratch—resistant technology. It is worth noting that lens materials are far more robust nowadays, and the plastic commonly used in their manufacture has intrinsic scratch—resistant properties. Sporting or shatter-proof lenses typically utilise polycarbonate materials, whose softer composition relies on scratch-resistant coatings for durability.

As many spectacle wearers will testify, acute fogging can be caused by rapid changes in temperature or ambient conditions. Using technology pioneered by NASA and now available at your local optician, anti-fog systems prevent the build-up of condensation.

You see what you eat

We frequently take our eyes for granted, but these highly specialised organs require careful maintenance to operate at their optimal capacity. While eye tests and vision correction products play key roles in this process, the foods we eat can also be greatly beneficial.

Studies around the world have emphasised that a healthy lifestyle combined with healthy eating can reduce the prevalence of cataracts, while carbohydrate- high, vitamin-low diets directly increase this risk. Similarly, a carefully balanced diet helps to counteract age-related macular degeneration, or AMD. This is the leading cause of registered blindness in the western world, but can be halted and even partly reversed through prompt diagnosis and positive lifestyle choices.

Research has established that obesity can double the risk of developing some common causes of blindness, including AMD. Although our retinas naturally weaken over time excess body weight can dramatically speed up the onset of AMD, giving us yet another reason to consider what we eat and how it might affect our bodies.

For many years, the focus on diet and its impact on our vision have concentrated on vitamins A. C and E.

Numerous scientific studies and clinical trials have shown that these three ingredients help to maintain healthy cells and tissues in our eyes, even assisting with our tear functions and reducing the symptoms of dry eyes. Should your diet not lend itself to a regular intake of fresh produce, nutritional supplements top up many missing vitamins and minerals, although use of these supplements should ideally be approved by your GP.

Colouring your judgement

There are many misconceptions about the condition known as “colour blindness”, or colour vision deficiency. This condition describes a decreased ability to see or differentiate varying colours. Colour vision deficiency is usually hereditary and is caused by an abnormality in the X chromosome explaining its far higher prevalence among males.

Our eyes work by using rods and cones, with the former processing vision in low light and the latter operating during brighter conditions.

The “normal” eye contains three separate cones, each responding to different light across the visible spectrum. Hereditary colour vision deficiency is a result of having less sensitive or non-functioning cones.

In its purest form - monochromacy, none of the cones work. This is an extremely rare inability to see any colours at all true colour blindness.

If there is a hereditary colour vision problem it is more likely to be a colour deficiency — seeing colours but not as many shades as those with full colour vision. The most common form of colour vision deficiency is anomalous trichromacy, where one of the three primary colours is less visible but not eliminated altogether.

Colour vision tests are strongly recommended for boys when visiting the optician. Simple pattern tests can determine a child’s ability to identify each of the three primary colours.

The impact of reduced colour vision upon careers can be significant and prove an insurmountable obstacle to some professions. However, most vocations are largely unaffected and even patients with monochromacy can lead a reasonably normal life.

There are eye conditions and general health issues that can change a person’s ability to see colour or its differing shades. If you notice your colour vision is not as good, you need to have this checked by your optometrist. Do not wait for your next routine check.