I will start with the new most familiar
ones which is commently and recently introduced to the malaysian...
There are many factors that could inhibit a person's ability to see the object hidden beneath the initial surface. The concept behind the creation of the stereogram is called eye dominance. Sometimes the brain will shut off one eye, and rely on the dominant eye, if the object to be viewed doesn't come in focus. There are many people who need corrected vision that don't realize it because of the human ability to adapt.
|figure 1.0...an image of a stereogram with an image of an helicopter...|