S503 – More to meet than eye

One of our greatest sense organs is our precious pair of eyes. We use our eyes to evaluate and sense our surroundings more than any other organs like ears and nose. Typically, we would tend to believe what we see, or rather what our eyes could capture. However, even our eyes may trick us at times, when what we perceive may not be what actually is.

Optical illusion is not a strange concept to us anymore, but how about a hidden image concealed within another? One good example is a stereogram. Instead of our eyes naturally capturing the wrong image in the case of optical illusions, we have to make our eyes capture a non-existent image in a stereogram unnaturally.

A stereogram is a diagram of repeated patterns, usually coloured. At first sight it may appear like an ordinary picture, but it actually contains a ‘hidden’ image waiting to be discovered. Sounds like decoding symbols or numbers? Let’s look at this stereogram.



Can you see anything other than small little starfish scattered around? Maybe not. Since it is ‘hidden’, how can it be so easily spotted? If you are thinking along the lines of ‘Picture Search’ or ‘Where’s Wally’, you will be very wrong.
Darting your vision around every inch of the stereogram does not work. Neither does staring at the picture intently. What we need is a special technique to enable us to ‘decode’ this image.

It is quite difficult to explain in words, but here it goes: Focus at the middle of the stereogram and relax your eyes. Try to look ‘beyond’ the picture rather than the ‘surface’. Then, cross your eyes such that the vision becomes doubled. This is when your left and right eye visions overlap each other. At the correct extent of overlapping, your visions will converge to form the hidden 3D image. This is the most difficult step to achieve, as you have to stay relax, remain cross-eyed and search for the correct focal point.

If everything goes well, you should notice some depth forming on the apparently flat picture. This is known as looking in 3D from a 2D surface. Somewhat similar to what 3D glasses do.

If you manage to see a big star in the middle, congratulations! You have succeeded in performing the special technique!

While you are getting excited over your new ‘powers’, here are some more stereograms to further satisfy your ability!


*Hint: Valentine's Day is coming!



*Hint: Feeling thirsty?



*Hint: Is that an UFO?


You should see a heart shape, a teapot and a flying eagle respectively.

Interesting? Probably yes to those who have acquired the technique. But maybe not to those who cannot seem to see any hidden images no matter how hard they try. When your eyes become tired, stop staring and try to relax. The more you strain your eyes, the more the image will not appear.

And oh, the distance from your eyes to the image doesn’t really matter. Don’t bother to stare close to the monitor and spoil your eyesight. The colour doesn’t matter too. You may print out the stereogram in monochrome and still be able to see the hidden image clearly. Enlarging the picture is not a solution.

Still cannot see? You may want to stop for today and try again tomorrow.