When we focus on a moving object we can smoothly move our eyes however if nothing is there we cant smoothly move them from left to right?


Not sure how to word it but let’s say you’re focusing on a bird in the sky moving our eyes move smoothly to follow it

however if you try and move your eyes from left to right with nothing there it cant be done smoothly you more or less focus on different random spots to move them from A to B

In: Biology

someone might explain it better. but our eyes are lenses . constantly adjusting based on how far the distance is.

when you focus on a moving object which is a predictable trajectory (e.g. bird) our eye locks focus and we can easily follow it.

when there is NOTHING . the distances vary as we move our eyes. (we cannot focus on nothingness which does not exist between your eyes and a far off distance) . so while you start moving your head. you might initially see something near like your next door building. then a pole maybe. then a far off building. then a far off monument . some people . heavily varying distances. and our eyes keep adjusting focus for them. working overtime. so it wont be smooth.

imagine a hypothetical bird which could instantly also move perpendicular to its flight of path. that too instantly (like a teleport kind of thing, nightcrawler from x men) . our eyes would similarly go crazy then.

one interesting thing you will see , especially in yesteryear’s special effects filled movies that actors are supposed to look at NOTHING (where a hologram or some cgi thing will be added later). and they are focus on all the wrong spots etc. and they look super weird since their eyes are not given a proper focus point.

Horizontal saccades (eye movements) feel like they are smooth, but they aren’t.
They are always somewhat jerky, but your brain corrects the visual input so that you interpret it as smooth movement.
When you have a moving object this allows the brain’s “correction software” to do a more convincing job of making you think it was a smooth movement.

I assume it’s similar to subconsciously breathing, or the heart beating away with no conscious effort; the muscles controlling where eyes are pointing are so finely balanced and in-tune with the brain that, given an object to focus on, they will aim towards it and stay aimed at it with little effort.

It’s a complex enough system to aim both eyes at a static object while the head is still, but if you look at something and move your head around, the eyes remain pinned on it. Add in the complication of the object in question moving while your head is moving and your eyes are rotating in their sockets to remain aimed at the object at all times, and it’s quite a dizzying amount of calculations and readjustments the brain and ocular muscles are having to do in realtime to stop your vision blurring or scooting off to the side.

It’s not much different to a sense of balance, where muscle groups work subconsciously to keep you upright and allow you to move around without consciously controlling each muscle in your leg, arm or torso to stop yourself falling over. The complexity of the system of staggering and I don’t have any sort of science to back it up, only room to marvel over the miracles of biology.