Optical illusions

Impossible Beach Cabin

Gianni Sarcone
impossible house sketch

With summer just around the corner, I find myself drifting back to the shores of time, to this delightfully impossible little structure perched on the beach.

A drawing concept created for a children’s coloring book on optical illusions. Over the years, I’ve explored this theme through many curious and playful variations.

impossible house

Are the kids engaging in creative activities inside the cabin or outside it?

The roof insists we’re looking at the exterior, while the floor pulls us firmly indoors. Both readings feel correct, yet they cancel each other out. So, there’s no clean resolution here—just a quiet visual paradox.

Curious to see more of my optical illusion book concepts, impossible worlds, and mind-bending creations? Take a stroll through my author page.

impossible house poster

The idea itself is far from new and has inspired countless artists, architects, and photographers. It even exists in three dimensions. A notable example is Roy Lichtenstein‘s House I (1996), an ingenious sculpture that appears to be a solid house but is actually a concave construction made of angled steel planes. As viewers move around it, the structure seems to rotate and reshape itself, turning perception into part of the artwork.

Speleology of Love – Figure–Ground Embrace

Gianni Sarcone

An illusion carved in emotion—can you spot the hidden lovers within?

I created this illustration for a commissioned series examining the underlying strata of interpersonal intimacy.

Gestalt vision

This black-and-white composition plays on figure–ground reversal. At first glance, it reads as a cave opening with a line of climbers moving along a rugged ridge. Look again, and the void resolves into the soft profile of two faces, suspended in the instant before a kiss.

Interested in commissioning my work to illustrate your next editorial project or conceptual series? Let’s discuss how we can bring your vision to light.

The stark contrast and clean silhouettes lend themselves naturally to large-scale applications. On a façade, the image finds a natural home as a mural in a Swiss village, where the alpine setting mirrors the climbers’ ascent.

Seeing Is Not What It Seems

Gianni Sarcone

Color is energy—an electromagnetic phenomenon shaped by how light is reflected from objects. What we call vision is not innate. It is largely learned, built through a slow and demanding process. We tend to take it for granted, yet someone born blind who later gains sight must spend years learning how to organize and interpret what now enters the eyes.

Seeing is neither simple nor passive. When we look at a landscape, color information reaches the visual cortex in roughly 30 milliseconds (in the occipital lobe, V1). Only a fraction later—around 70 milliseconds—shape, depth, and motion begin to emerge. In these brief intervals, the brain filters, compares, and reconstructs fragments of data, assembling them into a coherent image. What we perceive is not a direct recording of reality but a refined interpretation—an internal best guess shaped for meaning and action.

The way we see

I’ve long been intrigued by the way people with partial or total visual loss engage with the world. Any serious reflection on perception or optical illusion eventually meets its counterpoint. Understanding how they “see” without sight reveals the real weight of vision itself—and how inseparably it works with the other senses, each one calibrating the rest.

When we see, move, speak, and feel at once, what actually binds sight to touch or hearing? The truth is, we notice far less than we assume. We attend only to what matters in the moment. Without the constant support of the other senses, perception would collapse into confusion, because they operate quietly in the background, guiding everyday behavior.

A striking example comes from research on inattentional blindness. In a well-known 1999 experiment by Daniel Simons and Christopher Chabris, participants watched a video and counted basketball passes between two teams. Nearly 40 percent failed to notice a person in a gorilla suit walking through the scene, pausing, even dancing, before exiting. The demonstration is disarming in its simplicity: we do not see what we do not attend to—even when it stands directly in front of us.

→ Source.

Optical Waltz: Constant Motion, Perceived Oscillation

Gianni Sarcone

The blue and yellow arrows in this video seem to move up and down in a rhythmic dance—yet their motion is strictly horizontal and uniform. This illusion is a variation of the “Stepping Feet Motion” effect, first demonstrated by Stuart Anstis in 2003.

In the original phenomenon, two objects glide side by side at a constant speed across a striped background, but appear to alternately speed up and slow down, creating a stepping or oscillatory effect. The visual system misreads contrast differences as changes in motion, producing a false sense of vertical or staggered movement.

Different but Equal

Gianni Sarcone

It’s not uncommon to read, on a snack package, the phrase “with chocolate taste,” often printed in bold uppercase. The wording plays a subtle trick on the mind. Most people assume the product must contain chocolate. Yet a flavor is not a substance. More often than not, what we bite into carries only the impression—an illusion—of chocolate.

The same applies to color. Our brain is just as easily misled. Colors behave like flavors: they may smell—pardon… look—like a particular hue, but they are subjective sensations rather than fixed properties of the outside world. They shift with context, changing according to their surroundings. More striking still, identical colors can appear different under certain conditions, while different colors may look the same. This phenomenon is known as color induction.

Even texture plays a role. It can alter how we perceive a color’s intensity and tone. Take beer and an egg yolk: they may share the same orange hue and gradation. Yet the brain reads them differently. The glass and the liquid are perceived as translucent, so their color seems lighter, duller, more diluted. The yolk, by contrast, appears opaque, with a richer, more glossy, more solid color.

In this picture, the beer and the egg share exactly the same orange gradation.

Beyond Constructible Forms: The Undecidable Bars

Gianni Sarcone

In 1934, the Swedish artist Oscar Reutersvärd sketched a peculiar triangle made of small cubes, neatly aligned on an isometric grid. Everything looked geometrically sound—until the mind tried to assemble it in real space.

Soon after, Lionel Penrose and Roger Penrose published their famous Penrose Triangle—three beams joined by apparently right-angled joints—and M. C. Escher explored similar paradoxes in works such as Waterfall and Ascending and Descending.

This triangular paradox has distant echoes in ancient Greek geometry, but Reutersvärd gave it a clear visual form: the impossible figure.

That’s the charm of impossible figures: every part looks right, yet the whole quietly breaks reality.

I began exploring these paradoxical structures in the 1980s. My interest grew naturally from the meeting point of two inclinations: a mathematical curiosity about spatial logic and a visual fascination with form. Over time I produced many variations—sometimes rediscovering ideas that others had already touched upon, occasionally arriving at configurations that felt genuinely new. In geometry, complete novelty is rare; most discoveries emerge as unexpected turns within an existing landscape.

One example from that period is the study shown here, created in the late 1990s and titled Undecidable Bars.

© Gianni A. Sarcone, 1997-2001

Parallel bars appear to run calmly side by side, yet their connections quietly sabotage the logic of space. Perspective slips from one segment to another, forcing the eye to accept incompatible viewpoints at the same time.

Each element seems perfectly normal.
Together, they form a structure that cannot exist.

Some bars appear to pass through others; some join where no joint should be possible. The geometry behaves as if the object were bending through space, while every line still respects the conventions of perspective drawing.

The result is an undecidable figure—a form the eye can follow effortlessly, but the mind cannot reconstruct.

Available as fine art print from my online gallery.

Over the years I have created hundreds of images built on similar principles, across different formats and media. If these works interest you for a book, exhibition, or monograph, feel free to contact me.

Here’s a simple 18-frame animation of my Op Art piece—work in progress.

IF: The Two-State Threshold

Gianni Sarcone

I’ve always been drawn to impossible objects—those forms that slip between logic and illusion, never fully settling into one or the other.

This piece grew out of an old idea I felt compelled to revisit, almost as if reopening a long-forgotten door. A binary door, in fact—one that leads to two distinct worlds. Depending on how you look at it, it shifts, tilts, and reveals something else.

It starts with pencil on paper. A loose, intuitive phase where the form finds its way. From there, I move into FreeHand MS—an old tool I’ve never quite let go of. It still gives me a certain precision and feel I can’t replace. Finally, I refine the piece in Photoshop, adjusting, balancing, pushing it toward that delicate point where everything holds together.

There’s still work to be done. Something remains unresolved—but maybe that tension is part of what keeps it alive.

Master of Numbers

Gianni Sarcone

“The Master of Numbers” is an Op Art photomosaic portrait of the renowned physicist, created from a collection of photographs of numbers. Each detail contributes to a visual exploration of mathematics, perception, and pattern. The project took me two years to complete, photographing numbers in the most unusual places and objects, and bringing them together into a single portrait.


And a little secret: tucked inside the mosaic is a tiny portrait of me and my wife—a fun, hidden signature and a personal touch.

Limited edition posters and prints are available through my online gallery.

When Straight Paths Bend

Gianni Sarcone

First, observe the alignment of the red circles as they move in a straight vertical path, up and down. Then keep your gaze on one of the three Xs in the middle. What do you notice?

© Thornton, I. M., Riga, A., Zdravković, S., & Todorović, D. (2025). The Mainz-Linez Illusion. I-Perception, 16(6). https://journals.sagepub.com/doi/10.1177/2041669525139912

The red circles seem to drift away from their true physical trajectories, as if they were following the curves of the static lines. This perceptual shift is known as the “Mainz-Linez Illusion“.

When you keep your gaze on the central X, the moving dots shift into peripheral vision, where spatial resolution is limited and detail is reduced. The visual system compensates by interpolating missing information based on contextual cues and prior experience. As a result, the dots become perceptually “bound” to the nearby curved lines, as if threaded on them, and their straight vertical motion is misread as oscillating.

The Mainz-Linez phenomenon reflects a broader principle: peripheral vision is largely constructive. Under certain conditions, this predictive filling-in can also distort motion judgments in real-world tasks—such as driving—where events in the periphery may be misperceived.

When Water Decides to Defy Gravity

Gianni Sarcone

My minimalist tribute to M. C. Escher: an animated “impossible waterfall,” drawn frame by frame. It’s not exactly my usual artistic language, but I had great fun creating it, and I hope you’ll enjoy watching it as much as I enjoyed making it.

As you can see, the isometric structure links impossible angles to create a continuous water channel that appears to flow upward in a loop, falling from a high point yet seemingly returning to the top.

The “impossible waterfall,” reimagined in a lavish Rococo style, rendered as a surreal illustration for a book project.