Orthographic or surface dyslexia is a form of reading disorder characterized by deficits in visual processing of and visual memory for symbols. It is less well known than dysphonetic dyslexia and often overlooked.
In orthographic dyslexia, individuals have difficulty with: the rapid recognition of sight words; memory for specific spelling patterns; and encoding and retrieving shapes and contours of letters and words. Consequently, there is an over reliance on phonics which diminishes fluency, poor spelling, letter reversals and problems in quickly recognizing letters and words.
Instruments like the rapid naming subtests on the new WISC-V or the CTOPPS can be helpful as well as visual memory tasks. Individuals with visual processing deficits like visual scanning can also have difficulties with reading fluency because they frequently skip words or even lines.
It is important when assessing the presence of dyslexia to measure orthographic processing as well as phonological processing. Without this kind of comprehensive evaluation, a prescription of a phonics program for individuals with surface dyslexia can be incorrectly recommended and they will may little progress.