As our eyes move across the page they make a series of jerky movements. Whenever they come to rest on a word that is called a fixation.
Most people fixate once on each word across a line of print.
In order to make our speed increase we must take in more words with each fixation, rather than make our eyes move faster. Try to avoid focusing on every word, but rather look at groups of 2 to 3 words. Familiarize yourself with new words so you don't get stuck on them when you read them again. Determine your purpose before reading. If you only need main ideas, then allow yourself to skim the material.