On this pictures you can see vertical stripes or columns. They are repeated.at the hole area in 2.5 centimeters.spaces. Every stripe looks nearly similar. We can see differentes between them if we look at them precisely. When we look on the picture, our eyes look on a different places. Left eye sees the lewft column, while the right eye sees the right column, which is right beside. When the brain interprates the data about what the left eye and the right eye observes, sees the difference beetween the columns and sees the depth. That's the whole secret!

         It is very exiting, becouse if we see this third dimmension, our eyes can wander (stroll) on a bib area.