Dyslexia is a specific learning disability that is neurobiological in origin. It is characterized by difficulties with accurate and/or fluent word recognition and by poor spelling and decoding abilities. These difficulties typically result from a deficit in the phonological component of language that is often unexpected in relation to other cognitive abilities and the provision of effective classroom instruction.
Secondary consequences may include problems in reading comprehension and reduced reading experience that can impede growth of vocabulary and background knowledge Dyslexia (or word-level reading difficulty) is predominantly characterized by a core deficit in phonological processing (the ability to recognize and manipulate speech sounds), which results in impairments in decoding (“sounding out” words), spelling, and word recognition.
These impairments almost always lead to difficulties in reading fluency and comprehension, reduced vocabulary, lower content knowledge, and a decline in overall school performance.