New Book · UK: 9 April 2026 · US: 16 June 2026
Unseen
Blind Spots and Why We Miss What Matters Most
About the Book
Every day, we fail to see things that are right in front of us, miss sudden or unexpected changes and fall for illusions without realising it. The culprit? Blind spots. These hidden gaps in our perception are responsible for errors in everything from operating machinery to diagnosing medical conditions, from giving evidence in court to how we invest our money.
Unseen is the product of a collaboration between neuropsychologist Dr David Lewis, voted one of the '50 Most Influential Psychologists in the World Today', and digital illusionist Keelan Leyser. Together, they explore the different types of blind spots, why they occur, how they can be exploited to manipulate our thoughts and behaviour, and the practical steps we can take to avoid them.
The book takes you from inattentional blindness and change blindness through to choice manipulation, expectation bias, facial recognition failures, the psychology of shopping and business decision-making, deepfake deceptions, social media manipulation and the art of magical misdirection. It introduces the concept of illusioneering, the deliberate exploitation of our cognitive biases for commercial, political or strategic gain, and reveals how to defend against it.
Using techniques drawn from both the magic stage and the psychology lab, Unseen exposes the blind spots that shape our lives and shows us how to see past them.
Featuring over 30 companion video demonstrations of the psychological and perceptual phenomena discussed in the book.
Inside the Book
Twelve Chapters on How Perception Fails
Experience the Blind Spots for Yourself
Unseen is accompanied by over 30 video demonstrations that let you experience the perceptual and psychological phenomena described in the book first-hand, from inattentional blindness to optical illusions, choice blindness to the power of priming. Access details are included in the book.
The Story Behind the Book
A Personal Note
Unseen represents the final creation of the Lewis and Leyser collaboration. I first met David Lewis while studying Philosophy and Economics at UCL, and he gave me my start in this career. Over three years we combined my experience as a performer and illusionist with David's decades of academic research to create something we both believed in deeply: a book that uses the world of magic and illusion to reveal the hidden workings of the human mind.
David passed away peacefully in July 2025. This book is dedicated to his memory, and I am proud to bring our shared work into the world.
— Keelan Leyser
About the Authors
Publication Details
Title
Unseen: Blind Spots and Why We Miss What Matters Most
Authors
David Lewis & Keelan Leyser
Publisher
Bloomsbury Sigma
Format
Hardback, 336 pages
Publication Date
UK: 9 April 2026 · US: 16 June 2026
ISBN
978-1-3994-2238-3
eBook ISBN
978-1-3994-2236-9
Also Available As
eBook & Audiobook
Order Your Copy
Available 9 April 2026 (UK) and 16 June 2026 (US). Pre-order now from Bloomsbury or your preferred retailer.
Pre-order from BloomsburyUK: Waterstones · Amazon UK
US: Barnes & Noble · Amazon US · Target