Other reading problems

Below are some of the different terms that are often used when talking about the various different types and combinations of underlying skill difficulties associated with poor reading.  The more difficulties a child has, the more severe their reading problem.

'Phonological Dyslexia'
This is what people generally mean when they are talking about dyslexia.  It is when a student has a phonological awareness deficit and has difficulty breaking words into sounds and then matching sounds with written letters, making it difficult for them to sound out or "decode" words.  Children with reading issues commonly have some degree of phonological dyslexia. This type of dyslexia is also sometimes referred to as dysphonetic dyslexia.

Rapid Naming Deficit
This is where children are unable to name letters and numbers quickly when they see them.  They may know the names of letters and numbers, but it takes them longer to name letters and numbers when there are many of them in a row.  Experts think rapid naming difficulty is connected with processing speed and that it may also be linked to reading speed.

'Double Deficit Dyslexia'
This 'type' of dyslexia occurs when a child has difficulties with both phonological awareness and naming speed.  
Children with problems in both these areas struggle with isolating sounds and are unable to name letters quickly when they see them.  This double deficit form of dyslexia is thought to be more severe and particularly challenging to treat.   

Working Memory Deficit
​Poor working memory is commonly associated with poor literacy skills.  Children who have difficulty holding onto bits of information in their head will find it difficult to read and spell words because they might forget the word they were trying to spell, the sounds that were in the word they are trying to spell, and might forget the whole word altogether.  They may also have difficulty with reading words because they cannot hold on to the sounds they are trying to blend in their head as well as with reading comprehension, because they cannot remember the information they have read.  Research has now shown that working memory is a powerful predictor of academic achievement, and that poor working memory is associated with poor learning outcomes.  

'Surface Dyslexia'
This is the 'type' of dyslexia where children have difficulty with whole word recognition and spelling.  There are words we all have to learn to read by sight because they cannot be pronounced using the normal rules of pronunciation.  Fluent readers also remember common words by sight because they have seen them so often. Children with surface dyslexia may have particular trouble with words that have tricky spellings and do not sound like they are spelled, and they may take longer to be able to recognise words as a whole by sight.  Surface dyslexia is also called visual dyslexia or dyseidetic dyslexia or orthographic dyslexia.  It is not uncommon for children to have both surface and phonological dyslexia.

'Visual Dyslexia'
​The term visual dyslexia means the same as surface dyslexia.  But some people use this term to mean something entirely different:  They think that reading issues have to do with the eyes and vision and may claim that reading can be improved through eye exercises or tinted lenses.  These methods are not endorsed because there is not enough evidence proving their effectiveness.

Other Dyslexias ... ?
You may hear about other kinds of dyslexia.  For example, the term directional dyslexia is sometimes used to refer to difficulty with sense of direction and telling left from right.  Most experts recognise this as a common problem for people with dyslexia but do not see it as a type of dyslexia on its own.  Some people also refer to something called math dyslexia. This is an inaccurate name for a brain-based math learning issue called dyscalculia, which is not a form of dyslexia.
Sources:
Retrieved from https://www.understood.org/en/learning-attention-issues/child-learning-disabilities/dyslexia/different-types-of-dyslexia on 18/01/2018