n. loss or impairment of the ability to comprehend written or printed words as a result of lesions, stroke, or other forms of neurological damage or disorder. It is generally seen in aphasia but may occur in isolation, in which case it is called pure alexia (or alexia without agraphia or agnosic alexia) and characterized by reading impairment with preserved language production and auditory comprehension. Individuals with pure alexia can also write but are frequently unable to read what they have written (hence it is also called word blindness). See also dyslexia.