If strabismus happened during this, double eye cannot look attentively at an object at the same time, pass brain center to produce two at the same time different and video, be disturbed each other and cannot look clear.

• 假如在此期间发生了斜视，双眼无法同时注视一个物体，传到大脑中枢就同时产生两个不同影像，相互干扰而无法看清。