keep staring at the black dot.after a while the gray haze around it will appear to shrink
问题描述：
keep staring at the black dot.after a while the gray haze around it will appear to shrink
答
注视着黑点部分,一会之后,你就会发现,它周围的灰色部分就会缩小.
你应该是在观察一个视觉变化图片吧?