Our eyes can't really "process" any FPS. Our eyes aren't cameras and don't really work the same way.

We do know, though, that 24 frames per second is the minimum amount after which we perceive a series of pictures as motion rather than individual shots. But just because that's the minimum doesn't mean we can't benefit from higher rates -- and apparently we do. 24 frames per second looks like motion, but 60 fps looks like smoother motion, and 144 fps looks even smoother, etc. There's probably an upper limit, too, and at some point it does become meaningless marketing stuff, but hey.

> There are plenty of blindtests that show the eye only can process up to 60 fps.

this is not how the eye works, we dont really process information the same way a camera would.

what we do understand is that 24 fps is the absolute mininum where you can " trick" the brain into believing its seeing motion.

if anythnig the true limitation of these higher rate displays is reaction time to motion

24 Hz is around the frequency where our brain no longer discerns discrete images as discrete but rather sees them as smooth motion.

However, our ability to detect motion itself is about 5 ms. If there's a tiger lurking in the brush and it leaps out to eat us, it only takes us about 5 ms to detect that tiger. This is equivalent to 200 Hz (although it's not strictly a periodic phenomenon).

Let's say you're watching a fast moving object. First it's here [X ]. Then it's here [ X]. If you're playing a video game and it moves that distance between frames, that's what you'll see. If you're watching a movie, you'll see something more like this [XXXXXX ] followed by [ XXXXXX] because there's motion blur. That's why a 24fps movie will seem much smoother than 24fps video game. It's because it's capturing the motion blur.

Now video games could simulate motion blur, but it's computationally expensive, and easier to just make many more frames and let your eyes/brain fill in the blur.

Nothing biological processes on a 'clock'. The closest thing we have is our heart, which is a terrible clock. It also doesn't stop everything else the instant it stutters (it takes a little while), which is a good thing for our survival.

Human eyes see the world through light, color, and sometimes motion. It's our brains that are adding most of the 'motion' that we see on a screen, and our brain is what limits/acknowledges the effects of different FPS. Because our brains are both good at ignoring details and can be trained, different FPS's work for different purposes.

'Cinematic' 24 FPS works in movies because we have been trained to accept it, but if we are controlling something on the screen we are more focused and we can notice differences easier. Comparisons are also easy to see the differences, because we are focusing on them.

(Also, an occasional cinematic trick is to have different FPS things on screen at once. It usually adds to the Uncanny effect, because the screen is doing something against what we were trained to expect)

The eye doesn't "process" in FPS. Instead, once a series of images reaches about 60 FPS, your brain stops interpreting them as individual images and instead interprets them as a continual "video. Above that, you can absolutely tell the difference in standardized framerates, but it's not as big as the difference in interpretation that happens at around 60 FPS.

We most assuredly can. As a gamer 30fps games can be problematic for me, causing motion sickness and nausea, if theres a lot of action and camera movement. Slower strategy games are fine. 60 fps I can tolerate decently, but may have some issues with fast camera spinning, but typically no nausea. 90fps is where I can spin the camera a lot more without worry of side effects. 120 and I can spin it like crazy and still keep track of targets, read a sign while driving a car in game, etc.

There was an article that fighter jet pilots can see changes around 200hz.
https://www.testufo.com/ is a good comparison to see at least 30 vs 60 as you most likely have a 60hz monitor. Some phones now support 144hz so you may have one and can check there to see the difference.

You may see the difference in quantity if you will follow a moving object with your eyes

In real world if you follow an object it's obviously not blurry at all

Let's say we are looking at a moving 40px circle
In 60FPS an object moving on 480px/second will jump by 8px every frame. The circle remains perfectly same, but as your eyes are following its position continuously, for your eyes it will be blurred between those 8 pixels, a whole 1/5 of the circle.
In 240fps the circle will be blurred by 2px, much less.

The same way you can differ a clean image on a screen from the same blurred image, you can differ the higher-frequirency moving image from a lower-frequirency one.

This also breaks eye's ability to properly follow the object, which breaks the immersion and may be felt by an average human without any extra tools

Our retina retains images for about 1/10 of second. If images change faster, our brain sees it as a motion. 24 fps means that every image remains 1/24 of second on our retina, so giving motion illusion. The fastest the changes, the smoothest the motion.