Dyslexia

Dyslexia is a language-based learning disorder. It causes its hosts to have difficulty decoding words and putting sounds of words together to make sense, although there is a lot more to it as well. It makes reading fluency, spelling, and reading comprehension very difficult. It can appear as just a difficulty, although, there are cases known when words flicker, lines of words merge together or separate, or words fly or fall off the page, which still makes reading and comprehending difficult. This is not in just the Percy Jackson world; ADHD is connected to dyslexia, and is often associated with a lot of other Learning Disabilities (LDs).
== Description ==
Those who suffer from dyslexia are often unable to decode words properly. This results in below grade reading and spelling skills. It has nothing to do with them seeing the letters wrong. It is a complexity with their brains being unable to recognize words and their sounds. In mortals, dyslexics have a dominant right brain, which makes it hard for the brain itself to interpret words because the right brain is used for mental images and more creative thinking. Because their left side of the brain does not work as persistently as the right, language takes longer voyages in order to be understood. 
However, through the Percy Jackson and the Olympians series and beyond, Percy Jackson, along with other demigods, suffer from dyslexia. This is explained to Percy by Annabeth Chase, who informs him that their dyslexia is a result of demigods' brains being "hard-wired" to interpret Ancient Greek, not English. It is usually coupled with ADHD. Demigod dyslexia makes English a difficult language to interpret. 
== Trivia ==
* While in actual terms, dyslexia covers both reading and writing, in technical/medical terms, it is limited to reading. The related written learning disorder is dysgraphia. Similar learning disorders include dyscalculia (affecting mathematics skills), and dyspraxia (affecting motor skills).  
* Unlike most demigods, Frank Zhang and Will Solace are not dyslexic and has competed in his school's spelling competitions.
* Rick Riordan's own son, Haley Riordan, has dyslexia, and this is one of the main reasons he made this a main characteristic of demigods.
* In the 1930's teachers called children who had dyslexia, lazy, according to The Son of Neptune.
* It is unknown if all minor demigods have dyslexia.