

Reading is the process of retrieving and comprehending some form of stored information or ideas.
The human capacity to read is accurately explained and predicted by human eye physiology and psychology. The eye is capable of taking in a certain amount of text using the vision span while fixating on the text. The sensory memory is able to hang onto the items in the vision span for a period of around 300 milliseconds. The short term memory, or working memory, can hold less material (around 4 items at a time), but for longer periods (around 30 seconds). These 4 or so items could be words, headings, or sentences, depending on the prior knowledge of the reader and the rate of reading within the well defined limits of human vision span. If the material is repeated or appropriately and meaningfully associated, it will be passed into the long term memory, which is potentially unlimited in capacity and can remain there from 10 minutes to indefinitely depending on depth of processing and subsequent recall.
A common test for children and adults is to ask them to read texts or words of increasing difficulty until they become unable to read or understand the words presented to them. This is used to determine what is called their reading age. For example, the average child of 10 will have a reading age of 10. But a 10-year-old child advanced in reading for his or her age may have a reading age of 12 or 13, i.e. may read to the level of the average 12- or 13-year-old. In a class of 12-year-olds of mixed ability, reading ages will typically vary from about 8 to about 16. Reading age is not simply a function of intelligence; a variety of teaching methods and practice techniques have been shown to have immediate effects on reading age. Reading ability tends not to increase after cessation of full-time education. The reading level of tabloid newspapers, although they are directed at adults, is around 9-12. Source: Wikipedia