Eyes are like the cameras of the mind. They snap the picture, but the mind interprets. Like a camera the eyes must focus on something before the image is seen. Skilled readers make 3-5 fixations per line, while inexperienced readers can make 10 or more. Reading is primarily a psychological process.
Eyes are simply an extension of the brain.
This concept can be seen as analogous to driving a standard shift car. In driving a standard car you use different gears at different times, depending on such factors as visibility, weather conditions, terrain, etc. No one, for example, always drives in second gear. If you use reading flexibility, you will realize there are four general reading rates, each appropriate to a different purpose. Skimming Rate - A high speed search for a specific fact, a very quick overview, or just the few important points.