Optical illusions

Ceci n’est pas une perspective

Gianni Sarcone

An impossible orange structure embedded in a surreal, Magritte-like painting.

This image is part of a book project exploring visual illusions through paintings inspired by the styles of well-known artists. The idea is to revisit familiar artistic languages—Magritte, Picasso, and others—through invented works that play with visual illusions, perspective, and perceptual paradoxes.

I’m developing this as a richly illustrated book for a broad audience interested in art, perception, and visual thinking.

I’d be interested in hearing from publishers or art-book editors who might like to explore the project.

Kinegrams: Optical Animations from Static Images

Gianni Sarcone

Two monks stood outside a temple, watching its flag wave in the wind.
“The flag moves,” said one.
“No, the wind moves,” said the other.A third monk smiled:
“Neither moves. Your mind moves.”

Back in the early 2000s, I ran a few public art workshops exploring a deceptively simple idea: a printed image does not have to move to appear animated.

The trick is a kinegram—a static image transformed into a precise pattern of lines. Place a special acetate screen over it, and the hidden movement suddenly appears.

No electronics. No screen. No animation software. Just a carefully calculated pattern and a bit of moiré.

In these workshops, we experimented with:
• concentric circles
• simple radial patterns
• geometric textures

The resulting kinegrams produce seamless, looping animations from completely static printed images. If you’re interested in exploring the technique or collaborating, feel free to contact me.

☞ More on kinegrams.

Horse in the Snow

Gianni Sarcone

Is the horse walking toward you or away from you?

Video: Alesia Willard (@rudniktheroan), British Columbia, Canada, 2024.


This is a case of “bistable perception“: the image contains ambiguous visual cues that allow the brain to construct two different interpretations.

The dark silhouette against the bright snow removes important depth cues—surface detail, shadows, and clear body contours. Occlusion between the legs also makes their spatial position difficult to determine. The brain therefore fills in missing information through “top-down processing“, drawing on expectations and prior visual experience.

The horse is actually walking away from the camera. The fascinating part is that the same ambiguous image can make your brain perceive two completely different directions.

Exploring Tessellations & Op Art: Hidden Arrows

Gianni Sarcone

This brief tutorial explores an Op Art tessellation that plays with bistable perception, figure–ground reversal and negative space. By combining modular geometric tiles with contrasting colors, the pattern creates a visual interplay in which arrows can be perceived as either foreground shapes or background forms, depending on how the pattern is interpreted.

Experiment 1:

· Preparation — Fig. A: Start with a 3 × 3 square. Divide it along its diagonals into four triangles, then add a 1 × 1 square to the outer side of each triangle, as shown. Color the resulting cross-shaped tile with two contrasting colors, ensuring that adjacent sections are different colors. The construction produces four inward-pointing arrows.

· Preparation — Fig. B: Following the construction shown, subdivide a 2 × 2 square to create five diamonds arranged in a staggered pattern. Use the same two contrasting colors. This produces a complementary tile containing four outward-pointing arrows.

· Assembly — Fig. C: The two tiles are complementary and fit together. Interlock the cross-shaped tiles with inward-pointing arrows and the square tiles containing the diamond pattern to create a continuous tessellation.

Visual result: The alternating geometric modules form a large geometric Op Art pattern in which arrows emerge through figure–ground reversal. And hidden within it are, believe it or not, 100 arrows. Yes, one hundred arrows!

This op art work is available as fine art prints and canvases from my online official gallery.

Experiment 2:

· Preparation — Fig. D: Build a four-armed pinwheel shape from a 4 × 4 square, as shown.

· Assembly — Fig. E: Interlock the four-armed pinwheel shape with the cross-shaped motifs containing the inward-pointing arrows.

· Assembly — Fig. F: As shown, these four-armed pinwheel shapes can be assembled in four or more different ways, producing different geometric configurations.

Visual Result: As seen in the example below, the contrasting colors make the bright blue arrows radiating around the pink central hubs—the pinwheel shapes—stand out, while the yellow arrows, matching the background color, virtually disappear from view.

pattern with pinwheel shapes

Experiment 3:

· Preparation & Assembly — Fig. G: Combine square tiles containing interior diamond arrangements with tiles featuring four inward- and four outward-pointing arrows formed by negative space. Arrange them alternately to create a checkerboard pattern.

The example below shows a 3 × 3 alternating checkerboard configuration that surprisingly reveals 52 arrows in total.

Variation: Here is a striking variation of the tile with four inward- and outward-pointing arrows. The inward arrows extend into continuous paths on a white background, creating the effect of interwoven arrowed ribbons.

Extra 3D Arrow Illusion

Let’s take a different direction from the experiments above and explore a 3D isometric illusion. This construction is inspired by classic impossible figures depicting ambiguous stacks of cubes, whose apparent number can change depending on how you interpret their spatial arrangement.

Start with a hexagonal boundary (Fig. 1) and overlay a triangular isometric grid (Fig. 2). Then draw six interlocking arrow shapes around a central point, folding their tails inward (Fig. 3).

Finally, use three colors to shade the isometric planes, or apply directional line hatching, to give the flat arrows a three-dimensional, interlocking appearance.

Curious about the mathematics behind these impossible 3D arrows? Math lovers can explore the geometry and construction 👉 here.

Deconstructing impossibility

Gianni Sarcone

A quick study of impossible interlocking cubes, taking the same paradoxical geometry from line drawing to watercolor and high-contrast digital collage.

The drawings use isometric projection to represent a three-dimensional cubic structure. The geometry appears consistent at first, but the planes intersect in ways that cannot exist in physical space. What functions as a back face seamlessly projects forward to become a front face, creating a continuous spatial contradiction.

In Between the Strokes

Gianni Sarcone

These two minimalist Zen compositions exploit our brain’s tendency toward pareidolia and the Gestalt principle of closure: we instinctively connect isolated strokes, filling in what is missing until a familiar presence begins to emerge.

A few seemingly unrelated brushstrokes can be enough to suggest something—or someone—we recognize.

Can you see the hidden figures?

☞ For further exploration, visit my Subliminal Faces gallery.

How fast do we actually see the world?

Gianni Sarcone

Our visual system does not work like a camera shooting at a fixed number of frames per second. There is no single human “FPS.”

Reality is continuous, but our brain processes visual information on different time scales. Some visual mechanisms are remarkably fast; others are much slower. What we perceive depends on what we are looking at, the stimulus, its brightness and contrast, and even where it falls on the retina.

Flicker is a good example.

When a light flickers fast enough, we stop seeing individual flashes and perceive a steady light. But there is no universal cutoff such as 30 or 60 FPS. Under some conditions, humans can detect flicker well above 60 Hz, and the threshold changes with luminance, contrast, stimulus size, retinal location, and other factors.

And detecting a very brief visual event does not mean that we see at 250 FPS. Temporal resolution is not a single number. Different visual tasks have different limits.

Then there is the famous wagon-wheel illusion.

A spinning wheel can appear to slow down, stop, or even rotate backward. In films, this is a straightforward consequence of the camera sampling the motion at discrete intervals. Interestingly, similar effects can also occur under continuous illumination, suggesting that temporal sampling or aliasing may also occur within the visual system itself. The exact mechanism, however, is more complicated than simply saying that the brain “takes snapshots.”

And what about the feeling that time slows down during danger?

It can certainly feel that way. But experiments have found no evidence that frightening situations suddenly increase our temporal resolution—as if the brain switched to a higher frame rate. Instead, the experience seems to involve changes in attention, memory, and the way the event is reconstructed afterward.

So forget the idea that your brain runs at 30, 60, or 250 FPS.

There is no single frame rate for human vision.

We don’t simply record reality.

We construct our experience of it.

How minimal can a drawing be?

Gianni Sarcone

How far can you strip away a design and still leave it readable? Take almost everything out, and your brain will still fight to make sense of what’s left.

Here are two experiments in pushing that boundary:

  • 24 Configuration: The curve of the 2 flows straight into the diagonal of the 4. The brain uses the Gestalt principle of closure—filling in the missing pieces so you see two distinct digits sharing a single outline.
  • 45 Configuration: Standard typography is stripped back to raw vertical and horizontal lines. The crossbar of the 4 turns directly into the top curve of the 5, relying on your memory of numbers to decode the abstract shape instantly.

When you remove the noise, viewing becomes interactive. You aren’t just looking at a drawing—your mind is actively completing it.

👉 For more patterns, and mathematical curiosities, explore these number facts.

Train your brain by questioning your eyes

Gianni Sarcone

For many years, I collaborated with Publications International Ltd. (PIL) on the Brain Games™ series, creating hundreds of optical illusions for three books designed to challenge visual perception, observation, spatial reasoning, attention, and visual logic.

Optical illusions are more than visual tricks: they make the brain question its first interpretation, detect discrepancies, and construct a different explanation of what it sees. In that sense, they provide a stimulating workout for perception and reasoning.

I now put my expertise in visual perception and optical illusions at the service of publishers, educational institutions, medical centers, and other organizations looking for engaging ways to challenge and stimulate the mind.

Challenge your eyes. Make your brain work.

👉 Discover the latest book on Amazon

optical illusions - Brain Games

The Deceptive Oriental Fan

Gianni Sarcone

One of my earliest color illusions, created back in the 1990s, when I was immersed in exploring the physiology of color perception.

Do the pleated sections of the fan really have two different shades of brown?

They don’t. Every pleated “accordion” section is exactly the same brown. Only the thin light and dark bands bordering each fold differ. Those subtle edge contrasts trick your visual system into seeing alternating tones where none exist.

The color is perfectly uniform, but your brain interprets it differently depending on the surrounding contrast—a classic example of simultaneous brightness contrast.