Persons with learning disabilities have average or above average intelligence, and their achievement deficits are not due to any sensory deficits. Furthermore, learning disabilities are permanent, neurologically-based conditions. Dyslexia is a reading disorder that can include difficulty in tracking and visual perception. Many students report seeing letters moving on the page and letter reversals.
Dysgraphia is a writing disorder.
Persons with dysgraphia may have illegible penmanship, often misspell words, have difficulty using proper punctuation, and may not construct cohesive sentences or paragraphs. Dyscalculia is a computation disorder. Visual processing deficits affect an individual's ability to translate symbols. Persons with visual processing deficits have normal vision. However, they may have trouble with reading comprehension, have a slow reading rate, or may reread the same line or paragraph.