What is this disease called AMD ? (12)

Age-related macular degeneration (AMD) damages the central part of the retina, known as the macula. Here's a cross-section of the eye (the eye cut through from front to back):

Viewed through the front of the eye, the normal macula looks like this:

 The most common form of AMD is called "dry" AMD, It simply consists of tiny pale yellow spots in the macular area, and it looks like this:

The "dry" situation can persist, usually gradually worsening, over many many years; during this time the person may see normally or may notice a very gradual reduction in their central vision (the part needed for detailed activities such as reading, or recognising faces). But in a minority of cases it can quite suddenly convert to "wet" AMD, where blood vessels grow under the macular area, which looks like this:

 In this wet situation, the person usually notices sudden onset of distortion in their central vision, followed after some hours/days by complete loss of central vision - so suddenly they can't see to read or recognise faces. Because the wet form is heralded by distortion in the vision, people with dry AMD are often warned to come back to their eye doctor within 24 hours if they notice any  distorted vision, for example kinks in their view of door frames/window frames etc.

So the above illustrates that in both dry and wet forms of the disease, you lose your central vision, the bit you need for accurate detailed seeing; in the dry form it happens over many years, whereas in the wet form it happens over hours/days.