Have you ever wondered why we refer to a person as having 20/20 vision?

When you go to an optometrist, the first thing you usually see is one of those charts on the wall with a big ‘E’ at the top. These charts are called Snellen Eye Charts. They’re named after the Dutch ophthalmologist Herman Snellen, who developed them in 1862 to measure visual acuity.

With these charts, Snellen set a standard for measuring visual acuity that is still in place today all over the world. Globally, almost everyone uses the Snellen chart to check visual acuity.
Measurements of visual acuity are known as Snellen fractions. The first number – 20 – refers to the distance between the patient and the chart in feet. The second number refers to a line of text on the eye chart. The big letter ‘E’ at the top of the chart designates 20/200 visual acuity.

The phrase 20/20 vision is still used colloquially by most Australians, even eye doctors, even though Australia uses the metric system (20 feet equals six metres). Visual acuity is officially recorded as 6/6 in most countries throughout the world.

A common misunderstanding is that 20/20 vision means perfect vision. Actually, it only means that a person has visual acuity within the normal range.

If you have 20/20 vision, you can read a letter from 20 feet away that average people can also read from 20 feet away. If you have 20/200 vision, you can read a letter from 20 feet away that the average person can read from 200 feet away – which would mean you have very poor visual acuity.

A person with a visual acuity score between 20/70 and 20/400 has low vision, while visual acuity worse than 20/400 would be considered legally blind.

Better than ‘20/20?’Basically, the further you can read down the Snellen chart, the better your visual acuity. If you can read to line 8 on the Snellen chart (‘D E F P O T E C’), you have 20/20 vision. If you can read the line below that, you have 20/15 visual acuity, which is superior.

It is generally accepted that 20/10 vision is as high as you can go in visual acuity in humans — that occurs in less than 1% of the population (comparatively, eagles and other birds of prey are thought to have 20/5 vision).

There is more to vision than acuityMost people are surprised to learn that visual acuity is one aspect of a wide range of skills and abilities that can affect the quality of your vision and your eye health.
Visual acuity is only one of the tests performed by optometrists during a comprehensive eye exam. They also test for…

• Peripheral awareness
• Eye coordination
• Tracking
• Depth perception
• Ability to focus
• Colour vision

Beyond 20/20Too many people assume that they don’t need an eye exam because they believe they have 20/20 vision. However, visual acuity is only a part of overall eye health.

Among the most dangerous misconceptions that people have is that when there is something wrong with your eye health, you will immediately discover poor vision symptoms. Unfortunately, this isn’t the case. Regular eye examinations are essential for your to be able to detect degenerative eye diseases such as glaucoma, macular degeneration, and diabetic retinopathy in the early stages.
The best thing you can do for the well-being of your eyes, regardless of your visual acuity, is to book a regular eye exam with your local optometrist — especially if you are over 40, have diabetes or have a family history of glaucoma or cataracts.

The coronavirus disease of 2019 continues to change and evolve as it sweeps throughout the world, and, as it does our understanding of it is changing and evolving as well.

One of the things that is changing is our understanding of the relationship between COVID-19 and the eyes. For example, we know that COVID-19 can spread through the eyes when an infected person coughs or sneezes near your eye or if you touch an infected object before touching your eye. This is how flu viruses spread as well.

We also know that whilst the risk of transmission through the eyes is very low, healthcare professionals agree that taking precautions to avoid these transmissions is a good idea.

We also know that, in addition to being a portal for COVID-19, the eyes can also have coronavirus eye symptoms. And: the risk of that, too, is very low.
COVID Conjunctivitis. A very rare symptom of COVID-19 – which affects 1 to 3 per cent of people with COVID – is conjunctivitis (commonly called ‘pink eye).

Strictly speaking, if you are suffering with the symptoms of pink eye – redness or itchiness of the eye – without the symptoms of Covid 19, you probably just have pink eye or allergic conjunctivitis.

Allergic conjunctivitis is usually accompanied by intense itching and happens to both eyes at the same time. Often, it’s seasonal; it’s not contagious.

Viral conjunctivitis (pink eye) starts at one eye and spreads to the other. It’s highly contagious.

Pink eye is not a stand-alone symptom of COVID-19. If you or your child has been exposed to someone with COVID-19, or pink eye symptoms occur along with other COVID-19 symptoms like fever, breathing issues, lack of taste or smell, confusion, or cough, contact your medical provider for advice.

COVID-19 and Contact lenses: A number of experts and organisations have come forward to remind contact lens wearers that frequent handwashing with soap and water will protect them from exposure to the virus.

To drive the point home, the Centre for Ocular Research & Education (CORE) recently re-released a series of images from a 2018 study that shows the dramatic effect of good hand hygiene.

All eyecare health professionals agree – proper hand hygiene is the most important factor in preventing infections, of any kind, for contact lens wearers. If you are healthy, and are practicing proper hand hygiene, there is no need to stop wearing your contact lenses.

COVID-19 and Glasses: Did you know that glasses can help protect you from the Omicron virus?

Professor Mary-Louise McLaws, a Professor of Epidemiology of Hospital Infection and Infectious Diseases Control at the University of New South Wales, believes it is important to wear glasses to protect our eyes as they can be an entry point for the virus.

“With Omicron, one of the things I think we should be doing is telling people to look after their eyes – I ask them to wear glasses, sunglasses or anything to protect their eyes because their eyes have what’s called ACE2 receptor sites (entry points for the virus).

“If you are indoors in a shop and somebody has breathed out through their nose because they are not wearing their mask over their nose or not wearing a mask over their mouth then it could get into your eyes, so it would be great if people protected their eyes when they were indoors in a shopping mall,” said Prof. McLaws.

Eyecare Plus optometrists strictly adheres to all government health and safety advice to reduce the spread of COVID-19. This includes rigorous dedication to hand-hygiene and the use of PPE, such as surgical masks, gloves, eye protection and breath shields for equipment.

Eyecare Plus optometry practices carry out enhanced cleaning and disinfection of the patient environment on a regular basis.

https://www.eyecareplus.com.au/covid-19-and-the-eyes/

Sunlight is the most significant source of UV radiation and can damage various ocular tissues. The surface of the eye (snow blindness), the lenses (cataracts, also known as opacity) and the retina (solar maculopathy, macular degeneration) are in particular danger.
UV light consists of UV-A light (leads to skin tanning, but also skin ageing), UV-B light (leads to sunburn and skin cancer) and UV-C light (these are the most dangerous rays, but are almost completely blocked by the ozone layer).
What almost no one knows: Eyes can also get sunburn. The cornea and the conjunctiva are most affected. The highest risk is always when the sunlight is heavily reflected, something that can occur in a snow-covered landscape or when spending time by or in the water.
With the right glasses, however, everyone can optimally protect their eyes from dangerous UV rays. What you should keep in mind when purchasing a pair of sunglasses:

• UV light protection: Sunglasses that absorb at least 99% of UV rays or light rays up to 400 nm.
• Yellow filter: Also called blue blockers because they block all blue light. As a result, the eye perceives the surroundings in a yellowish tint. Benefit: Better contrast for very distant objects, especially on a cloudy or snowy day. Best suited for skiers, hunters, sailors and pilots.
• Polarisation filters: They block diffused light. For example, light reflected off water surfaces or cobble-stone pavement. Particularly useful for driving and fishing.
• Mirror lenses: They reduce the quantity of light reaching the eye, but do not offer any safe protection from UV radiation.
• Side protection: Sunglasses with this function protect the eyes from light entering from the sides.
• Gradient tint lenses: They are dark-coloured in the upper part of the spectacles, light-coloured in the bottom. They thus block the glare from above, but permit normal downward vision for the eyes. They are useful for drivers, but are not recommended for the beach or in snow because a strong glare can come from below.
• Photochromatic lenses: They darken automatically when it is bright and lighten when it is dark. Depending on the UV radiation and the temperature, these processes often take much less than five minutes thanks to new technologies.

Eye protection is also often recommended for medical reasons. This primarily applies to people with increased UV radiation risk. These include:

• Patients with macular and retinal degeneration. They should always wear glasses with a good UV filter when spending time outside.
• Patients after a cataract operation. These patients’ eyes are particularly sensitive to UV light because the natural lens has been removed and has been replaced by a plastic lens (intraocular lens). Sunglasses with 100% UV protection are necessary with older models because they absorb very little UV light. New intraocular lenses now have UV protection.
• Patients who are taking certain medication. Medication for psoriasis and active pharmaceutical ingredients such as tetracycline, doxycycline, allopurinol and phenothiazin are all so-called “photosensitive medications.” They increase the eye’s sensitivity to UV light. Your doctor will advise you about appropriate eye protection.
  

If your glasses are not optimally fitted, then there's no way you can benefit from your full visual potential. This can significantly impair your quality of life. Think about it: reading the menu in a restaurant becomes a nightmare or you feel insecure when driving. This raises several questions: can you damage your eyes if your glasses are too strong (overcorrection) or too weak (undercorrection)? What are the effects if your fields of vision are not ideally corrected? And does eye fatigue or 'poor' light – be it too bright or insufficient – pose a risk to your eyes?

Do you damage your eyes if your glasses are not optimally fitted?

No! Poorly fitted glasses don't have any long-term effect on the health of your eyes. However, we should distinguish between the eyes of an adult and the eyes of a child, the latter of which are still developing. If a pair of glasses is poorly fitted, then this can definitely impair the vision of children and young adults. Children are not emmetropic, meaning their vision is not ideal. A child's vision develops progressively: starting in its immediate vicinity, such as when looking at its mother, through the close-up range required later for painting or reading right up to 3D distance vision. In other words: this slight hyperopia is actually advantageous at first and is something which children ultimately gets used to with age. A pair of glasses can help children develop optimum vision. Visual defects don't damage adults' eyes – no matter if they're short-sighted, long-sighted, or if they wear the wrong glasses. Instead, your eyes 'learn' to correctly focus on different distances and to modify their visual performance, as well as possible, to accommodate the particular situation. If this happens over a longer period of time and requires greater effort from your eyes, then noticeable symptoms occur.

What are the negative consequences if glasses are not optimally fitted?

Glasses which are not optimally fitted to the wearer's eyes can lead to different symptoms. Here's a typical problem: you notice that your glasses don't provide you with unimpaired vision. This leads to a subjective deterioration of your vision. This doesn't cause damage, but it certainly strains your eyes. And it means that your eyes have to work harder. The possible consequences are numerous and include everything from headaches and neck pain, all the way to dizziness or double images. Burning or itchy eyes are another symptom. These aren't just a consequence of wearing the wrong pair of glasses. Dry air can also be the reason. However, an incorrectly fitted pair of glasses can contribute significantly to the problem.

Can you damage your eyes by wearing an incorrectly fitted pair of glasses for a longer period of time?

No, absolutely not. There are also no drawbacks if your visual performance deteriorates over time and your glasses, which had been optimally fitted, no longer provide ideal correction. You may not always realise that you're not benefiting from your full visual potential – you simply get used to this situation. Thus impaired visual performance is often only discovered by an objective source, i.e. when you're applying for a driving licence.

Carrots are good for the eyes – or have you ever seen a rabbit wearing glasses to prove otherwise? Not only is this comparison not very funny, it hasn't got a leg to stand on. And yet this health myth has been around for generations. The following is true, however: carrots contain a lot of beta-carotene. This is a precursor of the essential vitamin A. If this vitamin is lacking in your diet, it can have a negative impact on growth and the condition of your skin and hair. In extreme cases, it can even provoke night blindness. Most visual impairments, however, are usually the result of completely different causes.

There is an endless amount of popular wisdom that infiltrates our subconscious during childhood. Nowadays, most of these myths can be scientifically and unequivocally refuted. Some, however, do at least contain an element of truth. And what better example is there than the popular health myth "carrots are good for your eyes". But what is the reasoning behind this myth? The tasty vegetable contains a lot of beta-carotene. This substance is what gives carrots their orange colour, but it is also the precursor of the essential vitamin A, which really is good for the eyes. Nevertheless, this piece of wisdom only contains a grain of truth.

Nutritionists also refer to vitamin A as retinol. In fact, this name portends directly to the function it performs in the eye. The eye's retina contains cells that can produce a black and white image from even the slightest glimmer of light. Without retinol, no-one would be able to distinguish between the contrast of light and dark, and people requiring medical treatment for a critical vitamin A deficiency are even at risk of developing night blindness.

Luckily for us, this type of health complaint is very rare in our part of the world. What's more, there are plenty of foods which are even richer in vitamin A than carrots – such as spinach, cabbage or salad. Animal products, like liver for example, are even better, for they do not merely contain the precursor of vitamin A, they contain the vitamin itself.

So what is our conclusion? Munching regularly on carrots does indeed benefit your eyes, but it will not give you the improved vision you're hoping for. Now, like before, whether you're short-sighted or long-sighted, the only thing that can really help with the majority of visual impairments is a good pair of glasses.

Children do suffer from undetected vision problems, these may require diagnosis, ongoing monitoring or correction.  Your local optometrist can diagnose risks or problems in a 30 minute consultation, most consultations are bulk billed to Medicare. We recommend children have a full eye examination as they begin school (Age 5).

To allow our children the best chance to achieve their potential, as parents, we should be aware of some of the signs to look for;

* one or both eyes turning inwards towards the nose or outwards towards the ears
* pronounced tilting or turning of the head when your child is focusing on something
* continuous blinking of their eyes
* regular rubbing of their eyes
* red or blood shot eyes
* difficulty reading - common symptoms include skipping of words or lines, holding the book or technology close to their eyes
* complaints of head aches
* complaints about blurry vision or double vision
* squinting to enable clear focus off in the distance

Below are some hints to assist in keeping a healthy eye environment in your home;

* when reading always read with a light on and take regular breaks
* encourage children to take a break, spend some time outdoors, remember to wear your sunglasses when outdoors
* when in the car or outdoors wear sunglasses
* set a fixed duration for computer, smart phone or tablet use. if extended periods of use are present, encourage breaks
* promote healthy eating habits. Fruit, vegetables, nuts and fish are not only good for the human body, but great for our eyes. Antioxidants, Vitamin A and Omega 3 are all needed to keep or vision in best condition.

Do you know what Glaucoma is? Scenic Rim Optometrists have the knowledge and equipment to advise you if you are at risk of Glaucoma.

About 2% of Australians will develop glaucoma at some time in their life and there are usually no symptoms in the early stages.  Most glaucoma is inherited (genetic) and as a result direct family, parents, siblings and children. have up to ten times higher risk than others of developing glaucoma.  This works out to about a 1 in 4 chance of being affected in their lifetime.  There are an estimated 300,000 Australians with glaucoma but half are unaware.

As early detection and treatment protects against glaucoma blindness we think you should tell your family you have glaucoma and alert them to their own risk. Encourage each of your direct family to undergo a full eye examination, including an optic nerve check. Having a two-yearly review is also recommended.

Diabetes is the fastest growing chronic disease in Australia. Over 1.7 million Australians are living with diabetes and a further 280 Australians develop diabetes every day. Types of diabetes include, Type 1, an autoimmune condition that destroys insulin producing cells in the pancreas. Type 2, a metabolic condition where the pancreas is unable to produce enough insulin. Gestational, a metabolic condition which occurs during pregnancy in part due to pregnancy hormones, and in most cases disappears shortly after giving birth

Too much glucose, blood sugar, can cause problems all over your body, eyes included. In particular, there are four parts of the eye that are vulnerable to high blood sugar: the retina, the lens, the vitreous gel, and the optic nerve. The retina stretches over the back of the eye, kind of like a screen for the light that enters your eye. Images projected onto your retina are converted into signals your brain can interpret and transmitted through your optic nerve. Diabetics may develop a condition called diabetic retinopathy in which the blood vessels in your retina become damaged. The blood vessels could begin to leak, or new blood vessels can grow and obscure the retina. Either way, dark patches will begin to obscure vision, and even lead to blindness.

Diabetic Retinopathy

Non-proliferative (background) – The longer you have diabetes, the greater the risk of small blood vessels at the back of the eye being damaged by high blood glucose and high blood pressure. This can result in leakage and often progresses to blockage of the vessels that supply the retina with nutrients. This stage is called non-proliferative or background retinopathy and there may be no noticeable change in your vision.

Proliferative – Non-proliferative diabetic retinopathy can progress and the retina may grow new blood vessels. This advanced stage is called proliferative retinopathy. The new blood vessels are weaker and can bleed onto the retina or the vitreous, the jelly-like centre inside your eye. Vision can be affected, sometimes seriously and suddenly.