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Macular degeneration affects the macular at the back of the eye, impairing central vision. This section will explain the causes of AMD in more detail.
The macula is a small area in the centre of the retina. It is the centre-most part of the retina where the light comes to a focus when you are looking at an object, and is where detailed vision takes place and is responsible for sight in the centre of the field of vision.
What causes macular degeneration?
The retina and macula rest on another layer at the back of the eye (the choroid), which provides oxygen and nutrition to the retina and is responsible for clearing waste products. Between the retina and choroid is a thin membrane (Bruch's membrane) through which the nutrients and waste products pass. Abnormalities in Bruch's membrane cause macular degeneration either by blocking nutrition or causing blood vessels of the choroid to grow under the retina; these blood vessels destroy structures around them as they grow. If the cells in the macula deteriorate then the central part of your field of vision (what you can see) becomes blurred.
What is seen around the blurred area is relatively clear because the peripheral retina works normally. This means you will retain enough peripheral sight to see to get around, but activities which need close sight, such as reading, get more difficult.