Eye chart number). The denominator indicates the distance in feet at which a person with normal vision could stand to correctly identify the same symbols identified by the person tested. For example, a visual acuity of 20/20 is considered normal. Numerous types of eye charts exist and are used in various situations. For example, the Snellen chart is designed for use at 6 meters or 20 feet, and is thus appropriate for testing distance vision. There is often also a need to test a subject's vision at near or occupational tasks (such as reading or computer use). For these situations, a Rosenbaum
Word recognition last 20 years of work in cognitive psychology indicates that we use the letters within a word to recognize a word". Over time, other theories have been put forth proposing the mechanisms by which words are recognized in isolation, yet with both speed and accuracy. These theories focus more on the significance of individual letters and letter-shape recognition (ex. serial letter recognition and parallel letter recognition). Other factors such as saccadic eye movements and the linear relationship between letters also affect the way we recognize words. An article in "ScienceDaily" suggests that "early word recognition is key to lifelong reading