Op art

Relative Size Illusions

Gianni Sarcone

Here are two relative size illusions I described back in 1997 and 2013.

The first, called Sarcone’s Crosses, challenges classic illusions like the Ebbinghaus illusion (Titchener Circles, 1898) and the Obonai square illusion (1954). It features a cross (the test shape) surrounded by squares of different sizes.

As shown in Fig. 1.a, 1.b, and 1.c, the three blue crosses are all the same size — yet the one on the left (Fig. 1.a) appears larger. Surprisingly, the illusion still works even when smaller squares completely cover the cross (Fig. 1.c).

So, the size of surrounding shapes doesn’t always dictate how we perceive the central one.

In the second illusion (Fig. 2.a and 2.b), due to assimilation, the red diagonal inside the larger ellipse seems longer — but the blue line is actually the longest.

Perception loves to play tricks on us.

sarcone's relative sizze illusions

You can explore more of my illusions and visual inventions on my official site: giannisarcone.com

Julio Le Parc – Nihil novi sub sole…

Gianni Sarcone

Although I’ve been working in the field of Op Art since the mid-1980s, it’s important to recognize that the movement itself has a deeper history. It began to take shape in the 1960s, led by pioneering figures such as Victor Vasarely and Bridget Riley.

However, the artists who truly captivate me—the ones who expanded the language of perception—are often the outsiders. One such figure is Julio Le Parc (b. September 23, 1928), an Argentine-born artist whose practice bridges Op Art and kinetic art. Le Parc studied at the School of Fine Arts in Argentina and went on to co-found the Groupe de Recherche d’Art Visuel (GRAV). His work, honored with numerous awards, holds a prominent place in Latin American modernism.

Le Parc’s recurring themes—color, light, and movement—have always resonated with me. During the ’60s and ’70s, he explored light not just as a visual element but as a living, dynamic material. Yet by the late ’70s, his presence in the art world had faded; his output became sporadic, and for decades his work slipped quietly out of the international spotlight.

 Fortunately, recent years have witnessed a renewed appreciation of his explorations in light and movement, bringing his contributions once again to the attention of a wider public.

Artist’s Website: http://www.julioleparc.org

Book: Catalog of the artist’s first solo exhibition, Paris, November–December 1966. Text in French by Frank Popper.

Trama – A Strategy Game with an Artistic Twist

Gianni Sarcone
trama boardgame 2

Back in the ’90s, my board game Trama made waves for its fresh take on strategy and design. Imagine the logic of chess, but with a twist: neutral pieces that both players can use. The board—plexiglass with screen-printed art—echoes the feel of an Op Art piece, while the Galalith tokens add tactile charm.

There are several design variants, with boards featuring different color schemes and patterns. Some versions include holes or extruded circular reliefs to securely hold marbles instead of tokens—offering a fresh, sensory-rich experience.

trama variant 1
trama variant 2

· Curious? The full rulebook (in French) is 👉 here.
· More about 👉 Trama.

If you’re a manufacturer interested in bringing Trama back to the table, feel free to reach out.

trama news

Misdirection → Illusion → Aha! Moment…

Gianni Sarcone

How misdirection, illusion, and wonder shape my creative process.

The path from misdirection to revelation is at the heart of how illusion and wonder spark insight. Misdirection steers our attention—often subtly—away from what truly matters. It disrupts our expectations, creating a gap between what we see and what is. Within that gap lies the illusion: a crafted discrepancy, a visual or cognitive sleight-of-hand that unsettles our perception.

But the magic doesn’t end there. When the illusion is cracked—when the mind shifts, recalibrates, and sees—the famous Aha! moment erupts. That flash of understanding isn’t just delightful; it’s deeply educational. It rewires how we interpret the world.

This sequence—misdirection, illusion, revelation—mirrors the creative process itself. It shows how confusion, when carefully designed, can be a gateway to clarity. In the right hands, illusion is not deception—it’s a tool to awaken curiosity, stretch perception, and provoke insight. Wonder, in this sense, becomes a powerful cognitive catalyst.

That’s why my art and, I believe, my writing, revolve around this sense of wonder—arguably the most direct and playful route to that pleasurable, often conflicting moment of insight: the sudden discovery of something previously unknown.

Umbrella Illusion

Gianni Sarcone

One of my illusions from the late ’90s. Take a look at the colorful umbrellas in Figures A and B of the table below—are they the same or different? About 80% of people will say that Umbrella A has jagged, zigzag edges, while Umbrella B has a smooth, wavy outline. But here’s the trick—you’ve been fooled by the brightness contrast of the rays inside the umbrellas. In reality, both umbrellas are identical in shape, perfectly congruent.

This illusion works even when only the lines of the shapes are emphasized. As demonstrated in the table below, the outline of Umbrella A appears jagged and zigzagged, while Umbrella B seems to have, once again, a smooth, wavy outline.

This illusion shows a phenomenon called curvature blindness, which was rediscovered in 2017 by Japanese psychologist Kohske Takahashi. He created a powerful variant and studied its impact on how we perceive shapes.

© Kohske Takahashi – The wavy lines appear different depending on the background and how the repetitive dark color is applied to them.

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The Architecture of Light

Gianni Sarcone

Colors, though fundamentally phenomena of light, are not merely superficial aspects of perception. They play a structural role in organizing visual elements. For example, applying contrasting colors to a series of repetitive graphic patterns—while varying their distribution—can dramatically alter how they are perceived. This demonstrates how color is not just an embellishment but an active force in shaping visual reality.


As Goethe put it, “Colors are the deeds and sufferings of light.” More than a sensory experience, they influence our perception of space, depth, and meaning, revealing the intricate dialogue between vision and cognition.

🔍 Explore more about the illusion of colors.

Puzzling Colors: Red Between the Lines

Gianni Sarcone

Colors are not as fixed as they seem. The red you see might not be the same red someone else perceives. Your brain constantly interprets colors based on their surroundings, which can lead to surprising illusions.

Take this experiment inspired by the Munker-White effect: all the gray bars in the striped patterns are actually the same shade. Yet, next to blue lines, they appear bluish; beside mixed colors, they seem to shift tones. This is known as color assimilation—where a color takes on the influence of its neighbors.

The same illusion explains simultaneous brightness contrast. In the wine-pouring examples below, the liquid seems to change color in the glass. But actually, the red remains unchanged.

Here’s a simple animated variant of my project: Hard to believe, but the flow of wine stays the same shade of red all the way—from the bottle’s neck, through the pour, and even inside the glass. It’s only your perception that changes!

Even more striking—when cyan lines replace black ones, the liquid pouring from the bottle is actually gray from start to finish, yet it appears to turn into red wine in the glass. In reality, the red is just an illusion—your brain fills in the missing color where none exists.

🔴 See it for yourself! Fine art prints of my color experiments are available here:
👉 https://gianni-sarcone.pixels.com/featured/red-wine-gianni-sarcone.html

⚠ Copyright Notice: My artworks are protected. Any use must include proper credit and a link to the original source. Commercial use is strictly prohibited.

Mystic Flying Bat

Gianni Sarcone

Mystic Flying Bat is a mixed-media artwork I created back in 2010. It was the starting point for a series of pieces in a similar style, some of which I screen-printed using different color palettes. With this work, I wanted to invite viewers to think about an intriguing question: What is movement?

What makes this kinoptic artwork special is the way it creates the illusion of motion. As you look at it, the black bat seems to flutter, expand, or shift. But here’s the fascinating part—if you stare at it long enough and then close your eyes, a white bat will appear in your mind!

Kinoptic designs, like this one, play with our perception, making still images feel alive. It’s all about the clever use of contrasting colors and the precise arrangement of shapes.

Curious about how to create something like this yourself? I’ve put together a tutorial you can check out.

If you’d like to own a print or canvas of Mystic Flying Bat, you can find them here.

Hypnotic Disc

Gianni Sarcone

Take a moment to focus on the circular pattern. How many spirals do you see? The surprising answer is none. There are no spirals here—just alternating black and yellow discs, slightly off-center and layered to create a striking illusion of swirling depth and motion.

© G. Sarcone, 1990

I began crafting pieces like this in the early ’90s, drawing inspiration from Duchamp’s Rotoreliefs. I was captivated by how simple rotation could deceive the eye, inviting the viewer into a world of optical illusions. It’s a unique experience—seeing motion and depth in something entirely flat, both puzzling and mesmerizing.

This op art pattern comes to life across various mediums and transforms into artistic expressions on different objects. In my online gallery, you’ll find art prints and everyday items featuring this work, all available for purchase.

Gliding Patterns: The Anomalous Motion Illusion

Gianni Sarcone

Let your gaze wander across the image below. Do the shapes in the first and third rows seem to subtly shift leftward, while the second and fourth rows appear to glide rightward?

© Gianni A. Sarcone, Gliding Patterns, 1999

Now, let your gaze wander across the image below. Do the concentric circles appear to subtly counter-rotate?

© Gianni A. Sarcone, Counter-Rotating Circles, 1999

Why do these static images appear to move? This perceptual phenomenon, known as “anomalous motion” or “peripheral drift illusion”, results from the interplay of color contrast, luminance, and eye movements. It occurs due to a sawtooth luminance grating in the visual periphery, where a sequence of contrasting colors transitions from light to dark. The speed of the perceived motion is influenced by the frequency of microsaccadic eye movements.

In the 1990s, I began creating many of these fascinating images, experimenting with patterns and contrasts to bring this mesmerizing effect to life.

Fine art prints and merchandise of these mesmerizing pieces are available in my online gallery—a perfect addition to any space!