Do you think circle edges is fading?
Stare at the black dot in the middle. You should see the outer edges of the circle fade away!
In this test the pictures appear to be moving even though they are really still. This is an example of our eyes relaying information to the brain and not being able to clearly identify exactly what it is what we see through our conscious awareness. The effect is heightened because our eyes perceive depth through the stereo effect created through each of our eyes.