The problem in dyslexia is a linguistic one, not a visual one. Dyslexia in no way stems from any lack of intelligence. People with severe dyslexia can be brilliant.
The effects of dyslexia, in fact, vary from person to person. The only shared trait among people with dyslexia is that they read at levels significantly lower than typical for people of their age. Dyslexia is different from delayed reading development, which may reflect mental disability or cultural deprivation.
According to the International Dyslexia Association estimates that 10% of the Australian population have some of the symptoms of dyslexia, including slow or inaccurate reading, poor spelling, poor writing, or mixing up similar words.
It is estimated that boys are one-and-a-half to three times more likely to develop dyslexia than girls.
The Dyslexia Association in Australia states: "A dyslexic individual can be successful because of their abilities not in spite of. A dyslexic may struggle to succeed because of their negative experiences in the learning environment not because of dyslexia."
Dyslexia affects people of all ethnic backgrounds, although a person's native language can play an important role. A language where there is a clear connection between how a word is written and how it sounds, and consistent rules grammatical rules, such as in Italian and Spanish, can be more straightforward for a person with mild to moderate dyslexia to cope with.
However, languages such as English, where there is often no clear connection between the written form and sound, as in words such as "cough" and "dough," can be more challenging for a person with dyslexia.