For over 10 years, I’ve had the pleasure of collaborating with Focus, an Italian monthly popular science magazine published in Milan.
In October 2020, Focus released issue #336, which featured my article and optical illusions. This special edition included a 10-page dossier on visual perception, showcasing over 13 original illusions I created, complete with explanations.
The cover of this issue also featured a unique effect I designed for Focus. As you read the main title, the cover image moves, and, intriguingly, the title changes depending on your perspective—read closely, and it says ILLUSIONI; look from a distance, and it transforms into COSA VEDI?
Here is a neat optical illusion project I was commissioned by “Art of Play“. From one perspective, the grooves in the metal die-cut bookmark seem to be an abstract design but place the pattern against a solid background and a familiar figure pops into view!
Our visual system can interpret colors and shades in surprising ways. This 3×3 Tic-Tac-Toe grid, for example, showcases how easily our perception of brightness can be fooled.
Do you notice anything unusual in the grid below?
Show / Hide the Trick
The looping animation below brings the illusion to life, revealing the trick in action. That large green square behind the grid isn’t actually uniform—it’s made up of alternating dark and light green squares.
Our visual system works like a “comparative computer”. In fact, we never see colors in isolation, as the appearance of any color is affected by the colors surrounding it. So, under certain conditions, colors that are identical may appear different, while colors that are different may look the same. In our visual system there is a mechanism that enhances the contrast of the outline of an object relative to its background: it is called “lateral inhibition”.
Thus, even small differences in brightness between adjacent zones, or objects, are deliberately increased by our visual system and the brain to better distinguish them. But something strange happens when the brightness boundaries of the color zones are concealed: the cues the brain needs to trigger the lateral inhibition no longer exist and consequently we become blind to variations in color brightness, as shown in the animated gif.
“Everything we see hides another thing;
we always want to see what is hidden by what we see.” – René Magritte
My book “Fantastic Optical Illusions” (ISBN: 178739235X) features all the best and most interesting illusion types: ambiguous and impossible figures, hidden objects, color and brightness effects, length, size and shape misperceptions, illusory moving patterns and image paradoxes.
This best-selling book has been first printed in 2004, since then I have made important updates on the latest discoveries in the world of perception, to be sure the book will continue to amaze both the young and the adult reader. Available from Amazon UK and Amazon USA.
