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I’ve been seeing optical illusions like this for something like 60 years, and the never-fail tagline is always “You can’t trust your eyes!” The thing is always presented as a profound scientific lesson in human perception.
But it’s SLANTED science, science with a somewhat false editorial built into it, the whole aimed at achieving a little funhouse-type prank on the viewer. When I figured this out 30 or so years back, when I understood the REAL lesson, I stopped being impressed by optical illusions.
The real lesson is: Yes, your eyes can be fooled … on rare occasions. Note how much work has to go into these contrived examples. Someone has to work very hard, probably going through dozens of trials, before hitting on the final form of the “illusion.”
Note also that the illusion works only from a single, sharply limited viewpoint. Move a few inches to the side and the illusion breaks down completely. Rather than the eyes being fooled, they verify our sense of the real — even in the face of a significant effort to deceive.
Finally, we aren’t really talking about eyes, are we? We’re really talking about eyes hooked to a human brain, which is VERY GOOD at seeing the real world around us — better than just about anything alive. Presented with an optical illusion, natural or contrived, we naturally experiment with changing viewpoints, observation over time, other senses, the observational assistance of other people, and a certain amount of careful thought, until we see through the illusion.
The truth is, it’s actually very hard to fool a human’s eyes for very long. This is something we unconsciously know — so well that when we DO meet up with an optical illusion, we enjoy it immensely, playing and laughing at it, walking around it, studying it, until it loses its luster and becomes just another part of our sensory knowledge.
Contrived examples like this are useful, but the sole conclusion should never be “You can’t trust your senses.” It should be “Look out for these rare occasions when you can be briefly fooled but, other than that, you can trust your senses as THE prime tool for observing and understanding the world. Never let anyone tell you not to trust your own perceptions.”
This is one of an array of quasi-mystical declarations that tell us not to trust ourselves, either implying or outright saying we should instead trust some god, or some “authority” who speaks for that god.
Nobody’s saying human vision doesn’t have its limitations. But the real world is the real world, we evolved to live and prosper in it, and every one of us is qualified to witness and appreciate our surroundings.