Surface dyslexia, which is also often referred to as visual dyslexia, is a characterized by a difficulty with processing written information. People with this type of dyslexia often have trouble correctly identifying letters that look the same but are oriented differently from one another or words that form other words when read backward or when the letters are reordered. It is also common for people with this disorder to have trouble with words that are not spelled phonetically. The term surface dyslexia is used to describe the appearance of this disorder rather than the reason behind it.
People with surface dyslexia can have a variety of different symptoms, all of which make it difficult for the person to read. One of the more common symptoms is a difficulty remembering or seeing the difference between letters that are made from the same basic shape, such as b, d, p and q. Though each of these four letters is distinctive, they are all made from a rounded side and a straight side twice its length. Whole words can also easily be confused by people with this type of dyslexia, especially when the letters can be reordered to form different words such as "was" and "saw."
Oftentimes, people with surface dyslexia will not retain many whole words in their memories. Most words, even those that are frequently encountered in texts, need to be sounded out carefully in order to be read correctly. Even when sounding words out, people with this type of dyslexia may have difficulty because not all the letters in the word are processed in the brain. In many cases, people with this disorder may accidentally skip over letters or even whole words when reading, in part due to an inability to keep their place in the text.
Surface dyslexia may be either developmental or acquired. People with developmental dyslexia have an irregularity in the brain that causes the disorder. This type of dyslexia may develop at any point when the brain is developing and may be formed from a problem in the physical makeup of the brain or in a problem with the synaptic connections. For those with acquired dyslexia, the cause of the disorder may be learned along with whole-word rather than phonics based reading. This type of visual dyslexia can often be overcome but it may take a lot of retraining for a person to make new reading strategies second nature.