The reason we don't notice the darkening of the visual world when we blink may be because corollary discharge signals the visual centers to discount such darkening when blinks occur. In support of this hypothesis, it has been found that

A) Sensitivity to light is heightened around the time of a blink
B) Sensitivity to light is reduced around the time of a blink
C) Sensitivity to light is unaffected around the time of a blink
D) Sensitivity of the ciliary muscles changes around the time of a blink