The macula is the part of the retina that enables us to see colour and fine detail. If this area degenerates, we lose the central part of our vision.

AMD is an eye condition that affects the central part of the retina. It is an age-related process that can develop after a person reaches 50. The exact cause remains unknown, and there is currently no effective treatment for most cases of AMD.

The retina is a light-sensitive layer inside the eye that converts the light that comes in through the pupil into signals.These signals are then carried by the optic nerve to the brain to enable us to see.

The surface of the retina is covered by more than 100 million light-sensitive cells called rods and cones. The central part of the retina is pigmented and is known as the macula. (Within this area is a small yellow spot, the macula lutea, corresponding to the fovea, the focal point of light on the retina.) The rods and cones in the macula are responsible for our sharpest vision and most vivid perception of colour. The macula enables us to see what is straight in front of us as well as the fine detail, such as printed text and people's faces.

AMD tends to develop in two ways, 'dry' (about 85 per cent of cases) and 'wet' (the other 15 per cent).