Think of the eye like a camera. In a camera, light is focused by the lens onto a film, where an image is formed. In the eye, light passes through the cornea (a clear structure forming part of the front wall of the eye) and the lens where an image is then focused onto the retina. The retina is similar to the film of the camera. It is a thin, light sensitive nerve tissue that lines the inside of the back of the eye. The macula or center of the retina only covers about 5% of the retina, but is responsible for the most sensitive central vision, the vision that one uses for reading, driving, and recognizing people’s faces. The remainder of the retina is for used for side vision. The images are collected by the rods and cones in the retina, and transported via the optic nerve to the brain where the images are processed. Any disease process that affects the “film of the camera” or the “cable” can result in blurred vision.
Your eyes will be dilated so that your eye doctor can see a larger portion of your retina as shown in the diagram above.