Understanding Dyslexia: Are there Different “Types” of Dyslexia?


Causes of Dyslexia

The causes of dyslexia are not completely understood, but with the use of brain scans from an fMRI, brain imagery studies show that those with Dyslexia have difficulty learning to read despite conventional classroom experience, traditional instruction, average to above average intelligence, desire to learn and learning opportunity. Dyslexia is caused by a difficulty with the brain’s ability to process phonemes (these are the smallest units of speech that make words each word different from the other). Read here!

Dyslexia does not occur as a result of vision or hearing problems and is not and should not be mistaken for a lack of intelligence.

There is only one official  “type” of Dyslexia. Scientists have suggested there are sub-types of Dyslexia.  None of these have panned out successfully and are still heavily debated.   Intervention and research cannot be overstated, however; as it not only helps in early identification of children who are at the risk of becoming dyslexic but also allows for early educational interventions and better outcomes.


  • Phonological Dyslexia: This impacts the left side of the brain also known as the cerebral cortex. Dyslexia affects the ability to process sounds – to connect with the letters a child sees with its sound &  they can also struggle breaking syllables in a word apart. The struggles with dyslexia varies among dyslexic individuals, and in most cases, those who receive the appropriate early educational intervention would be academically successful throughout their lives. However, the effects of Dyslexia reach into writing, reading, and spelling even in their adult lives. The impact of the cerebral cortex is in certain cases, hereditary (passed down through gene lines).
  • Dyseidetic Dyslexia: Sometimes called, “Surface Dyslexia”.  Children sometimes struggle with sight recognition of words.  They will see & read a word on one page, but not recognize it on the next page.  Reading fluency and comprehension, as well as vocabulary development is affected.  However, this “type” of dyslexia is not supported well in describing a child’s reading struggles.

Usually if a child’s reading struggles are being discussed at school, they will not refer to any sub-types of Dyslexia.

Other “types” of Dyslexia debated:

You may hear other types “loosely” use the term Dyslexia incorrectly:

  • Visual dyslexia: This can refer to a range of things.  Also referred to as visual processing disorder or Surface Dyslexia,  is a term used to describe a condition where the brain’s ability to properly interpret visual signals is impaired.
  • Auditory dyslexia: Also referred to as Auditory Processing Disorder (APD) is similar in description to the visual processing disorder. Characteristics of APD can mirror those discovered with Dyslexia.  However, different interventions are needed for both. APD effects the brain’s ability to properly process and interpret the different pitches in sounds and speech.
  • Math Dyslexia: this is an inaccurate term used to describe a math processing difference called, Dyscalculia.

So, it is important to know that there is generally one “Type” of Dyslexia.  Struggles with Phonological Awareness makes it hard for children to make the sound/letter connections they need to in order to become successful readers.  Dyslexia “looks” different with each person.

Celebrate the differences in your students this month.  Read, “Fish in a Tree” by  Lynda Mullaly Hunt.  My 4th graders and I are listening to the book this month.  It has been amazing to hear their insights, but most of all how they connect with the main character, Ally.

Happy Monday!


Let's Connect both logos