Exhibition
OPTICAL ILLUSION
By Sugihara Kokichi
Optical Illusion – Flip Your Sight, Unlock Your Mind
When does perception become illusion? For the first time ever in Vietnam, from June 28 to August 24, 2025, in Hanoi, Japan Foundation Center for Cultural Exchange in Vietnam is proud to present the exhibition “Optical Illusion”, an eye-opening journey into the surprising world of visual perception that changes how we see and understand reality. The exhibition will showcase 53 three-dimensional illusions by Professor Sugihara Kokichi—a four-time winner of the International Best Illusion of the Year Contest and a pioneer in in applied mathematics and spatial cognition.
Unlike traditional optical illusions confined to flat surfaces, these are real, tangible models designed with precise geometric calculations. A shape that appears circular from one angle might reveal interlinked squares from another. A fish placed beside a mirror reflects only a skeleton. Some designs, as small as 8 centimeters in size yet produce stunning visual effects that continue to puzzle the keenest eyes—even when observed up close. While we often assume that our eyes enable us to perceive reality most accurately, Professor Sugihara humorously challenges this belief by exploiting the “blind spots” in our visual system. His illusions give rise to seemingly impossible phenomena that provoke curiosity and philosophical reflection: How far does biological function allow human to perceive so-called reality? Beyond sheer wonder, his work also sparks scientific thought and reveals the profound beauty linking mathematics, art, and human perception.
Having exhibited in Japan and numerous countries worldwide, Professor Sugihara has been exploring these visual phenomena since the early 2000s. His creations have been featured on various Japanese television programs including NHK’s “DESIGN TALK plus” and the famous idol group Arashi’s “Arashi ni Shiyagare” where they received praise and acclamation from a wide range of audience. Besides, his works have also been presented in top science and art museums around the globe, among which the National Palace Museum in Taipei can be named.
This exhibition offers one-of-a-kind opportunity for Vietnamese audience to access a rarely seen style excelling in mathematic precision and artistic creativity, promising a unique, delightful, and inspiring experience for visitors of all ages.
EVENT INFORMATION
■ Credits
Organized by: The Japan Foundation Center for Cultural Exchange in Vietnam
Artwork credit: Sugihara Kokichi
ABOUT THE PROFESSOR
Sugihara Kokichi earned his Master’s degree in Engineering from the University of Tokyo in 1973. He went on to work at various institutions, including the Electrotechnical Laboratory, Nagoya University, and the University of Tokyo, before joining Meiji University in 2009. Since April 2019, he has held the position of Distinguished Professor Emeritus at the Meiji Institute for Advanced Study of Mathematical Sciences. His field of expertise is Mathematical Engineering. While researching the development of robotic vision, he discovered methods to transform visual illusions into physical models and expanded his work into the field of three-dimensional optical illusions. He has created numerous seemingly impossible structures and continues to be active as an Opt Art model artist. A four-time winner and two-time runner-up of the International Best Illusion of the Year Contest, his illusionary artworks have been exhibited at numerous science centers and museums, including a notable special exhibition at the National Palace Museum in Taiwan, which ran for one year and eight months from September 2018 to May 2020.
■ Research Field
- Voronoi diagrams (robust construction methods, generalizations, applications)
- Design methods for geometry algorithms without risk of malfunction (topology-first approach, integer reduction method, symbolic perturbation method, error-absorbing representation)
- Computer vision and computer graphics (reversible Minkowski algebra, pixel-independent shape processing techniques)
- Mathematics of visual perception (optical illusions, anomalous figures, impossible 3D objects, stereoscopic vision, viewpoint tricks)
- Mesh generation for finite element methods (Delaunay tetrahedralization, mesh refinement, finite element methods that work on irregular meshes)
■ Awards (Recent Achievements)
- April 2015: “Ambiguous Garage Roof”, selected for the “Beauty of Science and Technology” panel exhibition
- June 2015: “Ambiguous Garage Roof”, 2nd Prize, 11th Best Illusion of the Year Contest
- November 2015: “Jumping Chicken”, awarded at the 7th Illusion Contest (Japanese Society for Basic Psychology)
- June 2016: “Ambiguous Cylinder Illusion: Rectangles and Circles”, 2nd Prize, 12th Best Illusion of the Year Contest
- September 2016: “Design Method for Footstep Illusion Art” (Hayato Ono, Akihiro Tomoeda, Kokichi Sugihara), Paper Award (Applied Category), Japan Society for Industrial and Applied Mathematics
- October 2016: “Arrow That Wants to Point Right”, awarded at the 8th Visual and Auditory Illusion Contest (Japanese Society for Basic Psychology)
- August 2017: “Caplicious Hearts”, finalist, Asian Digital Modeling Contest
- September 2017: “Partial Disappearance Illusion”, finalist, Best Illusion of the Year Contest 2017
- September 2017: “A New Type of Impossible Object That Becomes Partly Invisible in a Mirror”, JJIAM Division Paper Award, Japan Society for Industrial and Applied Mathematics
- October 2018: “Triply Ambiguous Object”, 1st Prize, Best Illusion of the Year Contest 2018
- December 2018: “Floating Playing Card Symbols and Flowers in a Mirror”, Grand Prize, 10th Digital Modeling Contest, Japan Society for Graphic Science
■Books (Recent Publications)
- Kokichi Sugihara: What Is Mathematics Good For?, Seibundo Shinkosha, Tokyo, 223 pages, 2017
- Supervised by Kokichi Sugihara: Transform with a Mirror!? Mysterious 3D Set – The Amazing World of Optical Illusions and Impossible Objects, Tokyo Shoseki, Tokyo, 2017
- Supervised by Kokichi Sugihara: Make It! Mysterious and Surprising! – Dr. Sugihara’s Trick Art Projects, Shufu to Seikatsu Sha, Tokyo, 64 pages, 2017
- Kokichi Sugihara: Illusion Trick Kit, Gentosha, Tokyo, 16 pages, 2017
- Kokichi Sugihara: Transform with a Mirror!? Mysterious 3D Set – The Amazing World of Optical Illusions and Impossible Objects, Tokyo Shoseki, Tokyo, 17 pages, 2017
- Kokichi Sugihara: Even When You Know, You’re Still Fooled – Illusion Quiz, Daiwa Bunko, Daiwa Shobo, Tokyo, 256 pages, 2018
- Kokichi Sugihara: New Illustrated Encyclopedia of Optical Illusions, Seibundo Shinkosha, Tokyo, 223 pages, 2018
■Research Papers in English (Recent Years)
- Kokichi Sugihara: Height reversal generated by rotation around a vertical axis. Journal of Mathematical Psychology, Tập 68-69 (2015), tr.7-12. http://dx.doi.org/10.1016/j.jmp.2015.07.001
- K. Sugihara: Ambiguous cylinders: A new class of impossible objects. Computer Aided Drafting, Design and manufacturing, Tập 25, Số 3 (2015), tr.19-25
- K. Sugihara: Anomalous Mirror Symmetry Generated by Optical Illusion. Symmetry, Tập 8, Số 4 (2016), tr.21, doi: 10.3390/sym8040021 (http://www.mdpi.com/2073-8994/8/4/21)
- K. Sugihara: A New Type of Impossible Objects That Become Partly Invisible in a Mirror. Tạp chí Toán học Công nghiệp và Ứng dụng Nhật Bản, Tập 33 (2016), tr.525-535. DOI: 10.1007/s13160-016-0233-9 http://link.springer.com/article/10.1007/s13160-016-0233-9
- J. Ono, A. Tomoeda và K. Sugihara: Footsteps Illusion Art. Tạp chí Toán học và Nghệ thuật, Tập 10 (2016), tr.65-73. DOI: 10.1080/17513472.2016.1236645. Online: http://dx.doi.org/10.1080/17513472.2016.1236645
- S. Chaidee và K. Sugihara: Fitting Spherical Laguerre Voronoi Diagrams to Real-World Tessellations Using Planar Photographic Images, J. Akiyama và cộng sự (biên tập): Hình học và Đồ họa rời rạc, tính toán (LNCS 9943), Springer, 2016, tr.73-84. DOI: 10.1007/978-3-319-48532-4_7
- K. Sugihara: Thickness Design for Ambiguous Cylinder Illusion. Tạp chí Toán học Công nghiệp và Ứng dụng Nhật Bản, DOI: 10.1007/s13160-017-0263-y, https://link.springer.com/article/10.1007/s13160-017-0263-y?wt_mc=Internal.Event.1.SEM.ArticleAuthorOnlineFirst , Tập 35, Số 1 (2018), tr.391-409
- K. Sugihara: Topology-disturbing objects: A new class of 3D optical illusion. Tạp chí Toán học và Nghệ thuật, Tập 12 (2018), Số 1, tr.2-18. https://doi.org/10.1080/17513472.2017.1368133
- T. Sushida, S. Kondo, K. Sugihara và M. Mimura: A differential equation model of retinal processing for understanding lightness optical illusions, Tạp chí Toán học Công nghiệp và Ứng dụng Nhật Bản, DOI: 10.1007/s13160-017-0272-x, Tập 35, Số 1 (2018), tr.117–156.
- S. Chaidee và K. Sugihara: Spherical Laguerre Voronoi diagram approximation to tessellations without generators. Graphical Models, Tập 95 (2018), tr.1–13.
- K. Sugihara và M. Moriguchi: Reflexively-Fused Cylinders. Symmetry, Tập 10, Số 7 (2018), tr.275, doi: 10.3390/sym10070275. PDF Version: http://www.mdpi.com/2073-8994/10/7/275/pdf
- S. Chaidee và K. Sugihara: Laguerre Voronoi Diagram as a Model for Generating the Tessellation Patterns on the Sphere. Graphs and Combinatorics, Ref.: Ms. No. GCOM-D-18-00005 DOI: https://doi.org/10.1007/s00373-019-02006-5 , https://link.springer.com/article/10.1007/s00373-019-02006-5
IMAGES FOR PR AND REFERENCES
Remarks: For the usage of the following images for your media, please kindly put the credit and information below, and please get the original size of the images at: (Photos of Artworks/Ảnh tác phẩm)
All photos credit: ©️ Sugihara Kokichi
■ For inquiries on the program, please contact:
Ms. Ngoc 024-3944-7419 (ext. 113) / Mr. Osuka (070-513-7550)
The Japan Foundation Center for Cultural Exchange in Vietnam
27 Quang Trung, Hoan Kiem, Hanoi, Vietnam
TEL 024-3944-7419
