Clear Eyes® Eye Care Blog

Abracadabra! Optical Illusions and Magic Tricks

Magicians have been wowing people with their acts for centuries. In fact, the first ever instance of the magic trick as we know it dates back to ancient Egypt. And today, from live shows in Las Vegas to movies to popular TV shows, magic tricks continue to thrill and amaze us. We watch in anticipation and when it’s over we’re left wondering, “How did he do that?”

The mystery keeps us guessing, even though we know there’s a logical answer. If it’s a simple trick like pulling an object out of a seemingly empty hat, you were fooled by sleight of hand, which is what happens when a magician fools you up-close with fine motor skills and dexterity.

But what about bigger tricks? How do those work? For example, there is Harry Houdini’s famous Vanishing Elephant trick where a real elephant walked into a large box on stage and then seemingly vanished when the box was re-opened. The elephant was simply gone. Surely, there’s more happening than sleight of hand, not to mention the fact that Houdini performed this trick in 1918 when they didn’t have the technology we have today.

The reason an astonishing magic trick like Houdini’s disappearing elephant works is because the magician persuades your brain into believing what your eyes see, even if it isn’t true—just like optical illusions. When in doubt, your brain makes assumptions.

The audience who saw the elephant disappear from the box actually saw a reflection of an empty box. The elephant was hidden behind a diagonally placed mirror in the box. In fact, mirrors and the use of light are secret weapons when it comes to trickery.

Another technique magicians use to play with your mind is the art of misdirection. This is the same phenomenon we see in optical illusions when the brain “fills in” the missing gaps. Misdirection works because when your attention is tightly focused on one thing, your senses are dulled to everything else in the surrounding field of perception.

Combine that with naturally occurring tricks your brain already plays on you—think blind spot—and you can’t help but be fooled. Magicians guide your gaze knowing they can control what you see, but more importantly, what you don’t see.

Every human has a blind spot, an anatomical hiccup, where your optic nerve and blood vessels leave the eye. Due to a lack of rods and cones, you can’t see something that exists in your blind spot.

You can find your blind spot with a simple test. Draw a small “X” on a piece of paper and draw a dot about 5 inches to the left of it. Cover your right eye and stare at the X on the paper. Slowly move the paper to your right and left. At some point, the dot will disappear from the paper and reappear. While you can still see the dot in your peripheral view, it will be gone in your blind spot.

As you dig deeper into the world of magic tricks, you realize magicians are more than mere entertainers. They are like experts in neurobiology—the scientific study of the nervous system. Of course, your eyes are the most important part, because you have to “see” magic to believe it.

What’s your favorite magic trick? Who’s your favorite magician? Let us know in the comments section on our Clear Eyes Facebook page.