Transcript:

Okay, take a look at this photo. So, in this photo, all these black lines that are moving around in a random manner, they are the eye movements that the eye does when it is viewing this photo. And it's a brilliant method by which the researchers actually tracked the movement of the eye when the observer was viewing the photo. 

The reason that these eye movements go in this haphazard manner, it's called saccade. It's French for jerky motion. So the eye does this jerky motion because the retina, which is on the back wall of the eye, is actually a low-resolution imager. The bulk of the retina does low-resolution imaging. The only part of the retina that does high-resolution imaging is the area that is fovea right next to the optic nerve. That's the only region of the eye or of the retina that does high-resolution imaging. 

So, the saccade motion of the eye is to bring all the parts of the picture in focus on the fovea region so that the brain can see in high definition. And it's a brilliant, absolutely brilliant engineering by nature!