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…
Blind spots are fine and I’ve known for years how to spot your own blind spot. You can make 2 spots on a paper separated by 4-5 inches, close your right eye and look at the right side spot with your left eye. If you do that and move forward or backward ( and rest at about 15 inches from the surface you drew on), you’d find a point where your left eye’s peripheral vision would not render the left side spot. You’d have found your blind spot.
But there is something more interesting, I never knew. You can actually see the blood vessels of your eye, with your own eye. Here’s how…
Take a sheet of paper (or card), and poke a pin hole in it. Then close one eye and holding paper close to your eye, jerk around the paper in little circles. At the same time, make sure you are looking at a bright white area through that hole. You could open up MS paint, make the whole canvas white and stare at it through the hole. Try to focus on the white screen and not the paper (or card)…
The video probably explains it better.
You probably know the static Ebbinghaus illusion – where a circle appears bigger around smaller circles even when it is of the same size. It’s static because it works without moving. Well, if you don’t know, you should because it helps you lose weight in a very subtle manner.
A slight variation involving movement of the Ebbinghaus illusion won the best illusion award for the year 2014. Yes, there are annual awards for the best illusions (I never knew that!). This one which won the award was submitted by researchers from the University of Nevada Reno.
The new variation is called the Dynamic Ebbinghaus effect. This is what happens in it…
There’s an arrangement of circles, exactly like the Ebbinghaus illusion, but there’s just one of the sets from the static illusion discussed above. While this arrangement of circles move, the central circle remains of the same size and the surrounding circles change in size.
Now, if you look into the central circle, you’ll see that it changes size too. In reality, it doesn’t. This effect is weaker when you look directly into the central circle. To make it more pronounced, you can shift your focus to the side and look at it through your peripheral vision. It’s totally mesmerizing. No wonder it won.
It works even when you know about it.