Magic Eye: seeing hidden images with our bare eyes
In today’s world, we have many different ways of entertaining ourselves. We can watch a movie, listen to music or read a book. But have you ever tried looking through a book – literally?
Si vous avez grandi dans les années 90, il y a de fortes chances que vous vous souveniez d’avoir vu traîner un livre appelé Magic Eye. Cette série se compose uniquement de visuels avec de nombreuses images colorées et des motifs répétitifs. Mais ce qui est cool avec ces images, c’est que si vous parvenez à tromper vos yeux de la bonne manière, vous commencez à voir des images et des formes cachées. Toute la page en deux dimensions tourne en trois dimensions sans avoir besoin de lunettes spéciales!
How it works
These repeating images, called auto stereograms, alter your depth perception. Since we are organisms with two eyes roughly 66 millimetres apart, they each see slightly different image. Our brain then merges them together, tricking us into thinking we see only one same image. Stereopsis translates to the words solid and appearance from Latin. It is the scientific term used to describe the depth perception in 3D images we can see with our binocular vision.
When you try and play with auto stereograms, you train your eyes to look through the page, making everything out of focus. If you do it correctly and end up being cross-eyed looking through the page, some parts of the image will start popping out. You will also be able to play with the depth by moving the page further away from your face – making the 3-dimensional images pop out even more. And all this is simply due to the fact you are focusing more on the two separate images your eyes see.
A little bit of history
The first image was created by the neuroscientist Bela Juresz in 1959. It was created using a grey scale and a dotted diagram, with darker patches making the background in the three dimensional state and the lighter patches the foreground. This was helpful in understanding the way we see. Using these images we discovered that depth is not perceived in the eye itself, but rather by the brain.
What’s the technique?
There are a few different ways of getting to see the pop-up images, but the one I find simplest is the following one. I bring the page close to my face, then cross my eyes. I then slowly move the page away from my eyes, keeping my eyes crossed, and then stop moving it when the 3D images appear. Once you are in the ‘3D-seeing’ phase, you can look around and enjoy!
When you feel like you start to get the hand of it, you can try and watch a music video by the musicians Young Rival which is entirely an animated auto stereogram: