Do you believe everything you see?
Look at the pink dots. - going around and around. Follow the movement of the rotating pink dot and all of tthe dots will remain only one colour, PINK!

However
if you stare at the black ' + ' in the centre, the moving dot turns to green!
Now, concentrate hard on the black ' + ' in the center of the picture.
After a short period, all the pink dots will slowly disappear, and you will only see only a single green dot rotating.
