By Anupum Pant
When you quickly move your eyes to focus on the seconds hand of an analogue clock, have you ever noticed that the first second you see actually seems to linger for a slightly longer time? Yes, it does. And there’s a reason why it happens.
When you rapidly move eyeballs to focus from one point to the another, it’s called a Saccade. If you ever try doing this rapid movement with a camera, a motion blur occurs in between the first point focus and the last point focus.
Unlike cameras our eyes (work closely with the brain) has a built-in mechanism to erase this motion blur. The brain erases all the motion blur during those few milliseconds and replaces the motion blur frames with the final image in the end.
This is why you see the longer first second when you quickly focus your eyes on the seconds hand – the stopped clock illusion or chronostasis. This also explains why you can never see your eyeballs moving when you try to spot their movement while staring at your own eyes on a mirror.
Michael Stevens from Vsauce explains…