I believe it was the Marx Brother's who first asked,"So who are you going to believe, me or your lying eyes?"  Could it be that what we currently see is more influenced by past experiences than what we are actually looking at?  Yup.

Here's the experiment.  Researchers from the NYU School of Medicine showed test participants a couple of dozen black and white images of animals and man-made objects that were obscured and degraded until they were difficult to recognize.
The subjects viewed each of the blurred images six times and then looked at a corresponding clear version of the same image, and then blurred images again six times after.  So the sequence is  blury /clear/ blury.
During this process, as the subject attempted to recognize each image they had their brains scanned. After seeing the clear version of each image, the participants were more than twice as likely to recognize what they were looking at when again shown the obscured version.
Study authors conclude that "what we recognize is influenced more by past experiences than by newly arriving sensory input from the eyes."
How does that influence your opinion of things like eyewitness accounts, UFO sightings, etc?