The 20/20 patient who can't read.

To understand how reading can be disrupted in patients with good acuity, it is important to realize the complexities that underlie this task, which normally seems so effortless. The process of reading is an interplay among vision, eye movements, attention, and linguistic processing, and impairments in any of these functions can result in reduced reading efficiency. The goal of this review is to provide a systematic review of these functions that can help clinicians generate a logical and useful differential diagnosis of impaired reading in the patient with 20/20 vision.