As an avid reader of Neal Stephenson, I was surprised not to find the phrase "Magic Eye" in this thread yet. There are many known ways to create optic illusion

As an avid reader of Neal Stephenson, I was surprised not to find the phrase "Magic Eye" in this thread yet. There are many known ways to create optic illusions that trick humans this quickly and thoroughly. Efficiency is the real question if you are concerned about deception and human brains.