Chris Marris is a special education teacher who mentors Stephen Wiltshire, encouraging his artistic talents and helping him with language development through his artwork.

Franco Magnani is an Italian artist with a remarkable ability to create highly detailed paintings of his birthplace in Italy from memory, reflecting his immersive recollections.

Greg F. is a young man who suffers from memory and vision loss due to a brain tumor that was left untreated during his time with the Hare Krishnas, leading to permanent neurological damage.

Jonathan I. is an artist who becomes color-blind after a car accident, eventually adapting his art to reflect his new achromatic perception of the world.

Margaret Hewson is a literary agent who helps nurture Stephen Wiltshire's talent by traveling with him to inspire new artistic creations.

Oliver Sacks is the neurologist and author who writes about unique neurological conditions, focusing on how individuals adapt to and are shaped by their experiences.

Robert Wasserman is an ophthalmologist who collaborates with Sacks, providing eye exams and insights into visual conditions affecting their patients.

Stephen Wiltshire is a British autistic savant known for his extraordinary ability to draw detailed cityscapes from memory and limited verbal communication.

Temple Grandin is an autistic author and animal scientist celebrated for her innovative designs in humane livestock handling, who offers perspective on living with Asperger's syndrome.

Virgil is a patient who undergoes surgery to restore his vision after decades of blindness, which leads to psychological and physical challenges as he adjusts to seeing.