In the valley of the blind, the one-eyed man is king.

Comprehension

Your ability to read increases both the acquisition of information and the preservation of that information, but humans have only been able to read using words and letters for about the last 3500 years. Prior to the development of reading with words and letters, knowledge was passed to new generations as oral history or in picture form. The concept of reading, however, was despised by some philosophers such as Socrates who viewed writing and reading as an abomination since he felt that memorization of words was the only way to fully appreciate and understand them. Socrates’ existence is actually known only through the heretical writings of his errant student Plato. While Socrates is known mostly for his teaching method and autocratic attitudes, he also advocated oligarchy over democracy. His death sentence from the city elders of Athens came not from his method of questioning but from his leading a violent revolution against democracy.

The significance of words as pictograms is demonstrated by the Cambridge University Comprehension example (below) in which virtually all of the words with four or more letters have intentionally had the internal letters jumbled. As long as the first and last letters of the word are the same, most people have little or no trouble "reading" and understanding the statement because the words are part of the comprehension pattern of the sentence.

What is critical is that the undistorted area of progressive glasses is smaller than the width of the phrases and multiple words. The lack of being able to clearly see those phrases and multiple words makes it difficult, if not impossible, for some people to comprehend the words and sentences.

OIny srmat poelpe can raed tihs. I cdnuolt blveiee taht I cluod aulaclty uesdnatnrd waht I was rdanieg. The phnaonamel pweor of the haumn mnid, aocdcrnig to a rshcaeerch at Cmarbgide Uinervtsiy, is taht it denso't metatr in waht oredr the lterets in a wrod are, the olny iprmonatt tinhg is taht the frist and Isat Itectr be in the rghit pclae. The rset can be a taotl mses and you can slitl raed it wouthit a porbelm.

(The source of this example is http://www.mrc-cbu.cam.ac.uk/people/matt.davis/Cmabrigde/ which has an excellent discussion of the concept.)