According to stroboscopic motion, when two vertical lines are flashed on a screen at different intervals, we perceive the lines in different ways. To be perceived as one line moving continuously from side to side, the interval between the lines should be:

scientific laws are the result of testing theories and proving them to be facts.

answer: the correct answer for the fill in the blank is rods.

rods are the specialized photoreceptor cells that are present in the retina of human eye. they are responsible for vision in the night time ( also called scotopic vision). they have very low visual acuity and color distinguishing ability.

as they are responsible for vision in night time, therefore they are found predominantly in the nocturnal animals.