translation.en: If you consider a child's eyes as a pair of biological cameras, they take one picture about every 200 milliseconds, the average time an eye movement is made.
translation.zh: 如果你把孩子的眼睛 都看作是生物照相机， 那他们每200毫秒就拍一张照。 ——这是眼球转动一次的平均时间。