Folks check this out. I am impressed.
http://sanjaal.com/taggedmails/20080906/very-cool-dynamic-optical-illusion/

Very Cool Dynamic Optical Illusion

Optical Illusion

DON’T  BELIEVE YOUR EYES…!!!

• If your eyes follow the movement of the rotating pink dot, you will only see one color, pink.
• If you stare at the the black + in the center, the moving dot turns to green.
• Now, concentrate on the black + in the center of the picture. After a short period of time, all the pink dots will slowly disappear, and you will only see a green dot rotating.

It’s amazing how our brain works. There really is no green dot, and the pink ones really don’t disappear. This should be proof enough, we don’t always see what we think we see and what we see is always not right.

it is truely amazing...thanks for posting.

nice one dude

Wow...

Of course there is a green dot. Try hiding all the pink balls with your hand and focus on only one ball. Each time it blinks, green dot appears for about 1/10th of a second. Look at it carefully.

Connection Failure

The picture is animated gif of 12 images..

The reason for this to happen is:

As you may already know, mixing two or more colors together yields different color. In this case, you are focusing on black color and the reflection of pink color is being mixed with black which produces green color.

Here are some other example of how mixing two or more colors produce different colors.

Googled a little bit and this is what I found:

This illusion works on a principle involving a trait human eyes have: the color sensitive areas actually get “fatigued” if they stare at an area with the same color for too long. As a result, you see the complementary color once you take your eyes off that area. In this case, because the pink dot at one position is there for all but one time when the animation has it disappear, you see the green dot there because you’ve stared at the pink for too long. Simple. If you stare at the picture for a while, then look away, you should see aring of green dots for a split second. Same principle.

he disappearance of all the pink dots is due to the brain’s trying to take a shortcut, and ends up combining the inverted pink with the real pink, leaving nothing but the grey background.