OPTICAL ILLUSION:
An optical illusion is characterized by visually perceived images that, at least in common sense terms, are deceptive or misleading. Therefore, the information gathered by the eye is processed by the brain to give, on the face of it, a percept that does not tally with a physical measurement of the stimulus source. A conventional assumption is that there are physiological illusions that occur naturally and cognitive illusions that can be demonstrated by specific visual tricks that say something more basic about how human perceptual systems work.

The above words (and the pic also) is from wiki

What we see "may be or may not be" true. To admit this I gave you the above pic. Actually the picture itself tells all. We do not see, we perceive. The act of seeing something is inseparably related to perceiving. When an image arrives at the retina, brain maps the image with our experience and convention. The sight is out come of these two.

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The words worked good as a wrapper na?
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