OPTICAL ILLUSIONS

During my research I came across some interesting optical illusions that also make one look closer at how we perceive things we see.

The most striking one, however simple, is Kanizsa triangle:

In the drawing we see a triangle although it is not drawn. The effect is known as subjective/illusory contour.                                                                        Also, the nonexistent white triangle appears to be brighter that the surrounding area but in face is the same brightness as the background.                          In a broader context this makes one wonder how much of what we see is objective and how much of visual information we receive is actually our brain's personal response to what we see.                              That then leads to two conclusions: firstly how we perceive the world around us is subjective; even if we share the same response it is likely that it will not be the same exact thing we are looking at.

Secondly, it is sometimes more important what we do not see but understand clearly from the picture. As the brightness of the triangle in the drawing suggests what we do not see becomes more apparent than the visible.

Another interesting optical illusion is Necker cube:

with all lines of equal weight there is no indication as to which is the front and which is the back of the cube.                                                              There are two possibilities as the two bottom drawings show, however the cube in its simplest form does not show which of them is correct.
This leads then to confusion and forces one's mind to skip between the two possibilities, as explained in Gestalt psychology theory.