Perceptual Adaptation

It might seem a daunting task to try and do almost anything while wearing glasses that invert your vision. Even something as simple as writing your name would become quite a challenge.

However, your brain being the amazing machine that it is, actually starts to adjust your senses to make the new stimulus more natural feeling. In fact, if you were to leave on the inverted glasses for a few days, your brain would even go so far as to invert the already inverted image so as to make you perceive things as upright once again (as tested by late 1800's psychologist, George Stratton).

Here is one more trick. Watch the center numbers that are counting down.

http://www.michaelbach.de/ot/cog_numerosity/

For the one second that the gray dots appear, you should notice that the side with the most colored dots now appear to have the least gray dots. In fact, both sides have the same amount of gray dots, with similar spacing between them. This is because your brain is registering the left side as 'more' and the right side as 'less'. So when the dots turn gray and equalize, the brain assumes that there are now less on the left side than there are on the right.