Dyslexic brains have trouble learning the correct scripts to connect sounds with written letters. You have problems storing the scripts in the left side of your brains as sight words. This gives you problems remembering the right words or breaking words down into their separate sounds.
You continue to sound the words out every time. To help sound out the words, dyslexic brains fire on both sides. You might even move your lips to use as much of your brain as possible to figure out the words, turning the letters back into sounds
Sounding out each word every time uses time and energy as lots of neurons in your brain fire inefficiently. The scripts are not very strong. It is a slow and tiring way to read.
Out of Time
We have, at most, two seconds to read a word and understand its meaning. If we don’t sound the word out in that time, we begin to forget it. Dyslexics often take a half second or more to sound a word out. If it is a hard word, it can take more than two seconds to decode. And so you begin to forget it.

Out of Energy
When really working on a problem, it is possible for anybody to literally run out of energy for higher-level thinking. People who are dyslexic work even harder than fluent readers to make letters make sense, and hold them in your brains long enough to understand the words. Because you have to work so hard at reading, your brain may use about five times more energy as fluent readers. Dyslexics work harder, and run out of energy faster and more often. This is why you may feel exhausted after a day at school.
Most people use about ten watts of energy to power their brain. When reading, dyslexics use five times more energy than fluent readers or 50 watts – about the same amount of energy as is needed to power a laptop computer!
To make reading automatic — to turn letters into a sight word — dyslexic readers have to see a word many more times than non-dyslexics do. But eventually, you being to recognize words without decoding them every time.
“Because of the dyslexia I always thought I had to work twice as hard as everyone else just to go the same distance.”
– Orlando Bloom, star of Lord of the Rings, Pirates of the Caribbean, and Blackhawk Down
For many dyslexics, reading may always be slow. It may never be fun. Writing may always have mistakes. Those are hard facts for you to deal with.
But dyslexics have other strengths.
References
Armstrong, Thomas. 2003. “Coming to Grips with the Musculature of Words.” In The Multiple Intelligences of Reading and Writing: Making the Words Come Alive.
Association for Supervision & Curriculum Development. http://www.ascd.org/publications/books/102280/chapters/Coming-to-Grips-with-the-Musculature-of-Words.aspx.
Beilock, Sian. 2010. Choke: What the Secrets of the Brain Reveal about Getting It Right When You Have To. 1st Free Press hardcover ed. New York: Free Press.
Bloom, Orlando. “Orlando Bloom.” Search Quotes. Accessed November 9, 2017a. http://www.searchquotes.com/quotation/Because_of_the_dyslexia_I_always_thought_I_had_to_work_twice_as_hard_as_everyone_else_just_to_go_the/340019/.
Eide, Brock, and Fernette Eide. 2011. The Dyslexic Advantage: Unlocking the Hidden Potential of the Dyslexic Brain. New York: Hudson Street Press.
Nicolson, Rod, and Angela Fawcett. 2008. Dyslexia, Learning, and the Brain. Cambridge, Mass: MIT Press.
Shaywitz, Sally E. 1996. “Dyslexia.” Scientific American, 1996:98-104.
———. 2003. Overcoming Dyslexia: A New and Complete Science-Based Program for Reading Problems at Any Level. 1st ed. New York: Knopf.
“Dyslexic Kids’ Brains Work Harder.” 1999. University of Washington Alumni Magazine. Learning Curves. October 6, 1999. https://www.washington.edu/alumni/columns/dec99/dyslexia.html.
Wolf, Maryanne. 2007. Proust and the Squid: The Story and Science of the Reading Brain. 1st ed. New York, N.Y.: Harper.
Wood, Tracey. 2006. Overcoming Dyslexia for Dummies. – For Dummies. Hoboken, NJ: Wiley.
Zimmer, Carl. 2006. “You’re a Dim Bulb (And I Mean That in the Best Possible Way).” The Loom. DISCOVER Magazine. March 23, 2006. http://blogs.discovermagazine.com/loom/?p=359.