Eye Problems

What Are Optical Illusions?

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An optical illusion is something that deceives the eye by appearing to be other than it is. They use patterns, colour and light to create the deception.

We have five main senses – sight, hearing, taste, touch and smell – however most information we receive from the world around us comes via our eyes. This might make sight the most important of all the senses, although let us not underestimate our ability hear a cow moo, touch a feather, smell a beautiful rose or taste an hot apple pie.

Vision depends on our eyes to see and on our brain to convert what we see into images.

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When we look at an optical illusion we may think are we seeing things? Are our eyes deceiving us?

An illusion is proof that we don’t always see what we think we do because of the way our brain interprets the image, we are looking at something that confuses our brain.

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To demonstrate, I particularly like this quote from on http://www.archimedes-lab.org:

Unfortunately (or fortunately?), seeing isn’t some kind of direct perception of reality. Atcually, our bairns are cnostanlty itnerperting, corrceting and gviing srtuctrues to the viusal ipnut form our eeys.

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A mirage and a rainbow are not illusions, they are known as optical phenomena. They are events you can see as a result of light from the sun or moon interacting with the atmosphere, clouds, water and dust.

by John Owens – http://www.john@ezidlabels.comhttp://www.ezidlabels.com

What is Diabetic Retinopathy

I have just heard that one of my relatives who has diabetes has just be diagnosed with a vision problem called Diabetic Retinopathy, so I have done some research and here is a short explanation that may help you or someone you know.

Diabetic retinopathy is a complication of diabetes which affects the tiny blood vessels in the light-sensitive tissue called the retina that lines the back of the eye. The retina detects light and converts it to signals sent through the optic nerve to the brain. Diabetic retinopathy can cause the blood vessels to bleed or leak fluid, thereby distorting vision. Without treatment, diabetic retinopathy can cause loss of vision and blindness.

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Diabetes interferes with the body’s ability to use and store sugar. The disease is characterised by too much sugar in the blood, which can cause damage throughout the body. Low vision is one symptom of diabetes, other symptoms include:

  • increased thirst and hunger
  • weight gain or loss
  • fatigue
  • frequent urination
  • skin infections, and wounds that heal slowly

Diabetic retinopathy affects a large percentage of all patients who have had diabetes for 20 years or more. It is also one the leading causes of blindness for people aged 20 to 64 years.

Often diabetic retinopathy may not be detected until vision loss occurs so people with diabetes should get a comprehensive eye examination when diabetes is first diagnosed and then these tests should be repeated on a regular basis. Early diagnosis and treatment can usually prevent severe vision loss.

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Studies have shown that controlling diabetes can slow the onset and worsening of diabetic retinopathy. People who monitor and maintain a normal glucose level are significantly less likely to develop the disease than those who don’t. Good glucose control also reduces the likelihood of developing other health problems including kidney and nerve diseases. Trials have also shown that controlling blood pressure and cholesterol levels and avoiding tobacco can also reduce the risk of vision loss.

There are several therapies that may be used alone or in combination for treating the disease and reducing vision loss, however they are not a cure for the disease. These treatments are:

  • Laser surgery – the heat from a laser is used to seal or destroy the leaking blood vessels in the retina.
  • Medication – several medications are available to be used in the treatment of diabetic retinopathy. These medications are injected into the eye.
  • Vitrectomy – this treatment involves the use of surgical instruments to remove the damaged blood vessels. Removing this material allows light rays to focus on the retina again.

Vision lost caused by diabetic retinopathy is sometimes irreversible. However, early detection, regular monitoring and treatment can reduce the risk of blindness by a significant amount.

Our goal at EZiD is to assist all people living with low vision by simplifying some of the decisions they have to make every day, for more information about how we can help please use this link.

by John Owens – john@ezidlabels.comhttp://www.ezidlabels.com

What is Macular Degeneration?

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Macular degeneration is the leading cause of severe vision loss in people over age 60. Because the disease develops as a person ages, it is often referred to as age-related macular degeneration (AMD) and it can be a source of significant visual disability. I have AMD. It occurs when the retina’s small central portion, known as the macula, deteriorates. The retina, which sits at the back of the eye, is a thin layer of tissue containing millions of tiny light-sensing nerve cells. It records the images we see and sends them via the optic nerve from the eye to the brain.

The macula is responsible for central vision in the eye, and it controls your ability to read, drive a car, recognise faces and colours, and see objects in fine detail.

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When the macula’s cells deteriorate, images are not received correctly. Initially macular degeneration does not affect vision. However, if the disease progresses, people experience a gradual decline in their ability to see object clearly and distorted vision. If the condition continues to worsen they will see dark or empty spaces blocking the central field of vision and diminished colour vision central vision.

Even so, because the rest of the retina is still working, they retain their peripheral vision, which is not as clear as central vision. At present macular degeneration is considered an incurable eye disease.

There are two main types of age-related macular degeneration:

Dry form. The “dry” form of macular degeneration is characterised by the presence of deposits, called drusen, in the macula. A few small drusen may not cause changes in vision; however, if they grow in size and number they may lead to the symptoms people find most noticeable when they read. In more advanced stages there is also a thinning of the light-sensitive layer of cells in the macula leading to tissue death.

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Photo taken in 2014 showing the drusen in my right eye.

Wet form. The “wet” form of macular degeneration is characterised by the growth of abnormal blood vessels underneath the macula. These blood vessels leak blood and fluid into the retina, causing distortion of vision that makes straight lines look wavy, as well as blind spots and loss of central vision.

How is AMD Treated? Some doctors recommend vitamin supplements to reduce the progression of Dry AMD. I live in Sydney Australia and the treatment I adhere to includes taking vitamin supplements daily and I can confirm that my AMD has not deteriorated since I was first diagnosed 5 years ago.

The main treatment for wet AMD is injections of Lucentis. This treatment targets the VEGF protein (Vascular Endothelia Growth Factor). This protein promotes the growth of abnormal blood vessels in the retina. These injections may prevent further loss of vision.

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John Owens – 2016 john@ezidlabels.com   www.ezidlabels.com