What is the magic eye?

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It is a technique in which people change the focus of their eyes to overlap the two pictures as one. They can then spot the differences very easily, which appear as glimmering objects. Differences can be spotted in mere seconds instead of minutes. It is called magic eye, based on the Magic Eye autostereogram books popularized int he 1990's, which uses the same eye technique. There are multiple Facebook sites that teaches you how to train yourself to learn either the cross eye method or the parallel method. Here is one such site: https://www.facebook.com/groups/1169317623484157