How Does Vision Work?
When you look at an image, light enters the eye through the pupil and strikes the lens. The lens bends the light, focusing it on the back of the eye - the retina. The light is converted into neural signals passed along the optic nerve to your brain which tells you what you are looking at.
The oval shaped area in your eye that captures the details of the image is called the macula. When the macula is damaged, as with macular degeneration, the image your eye captures will lose its definition and appear blurred.