We have had machines that do what you describe for decades.
Here's Daniel Dennett in Consciousness Explained (1992)
When your eyes dart about in saccades, the muscular contractions that cause the eyeballs to rotate are ballistic actions: Your fixation points are unguided missiles whose trajectories at lift-off determine where and when they will hit ground zero at a new target ...
Amazingly, a computer equipped with an automatic eye-tracker can detect and analyse the lift-off in the first few milliseconds of a saccade, calculate where ground zero will be, and before the saccade is over, erase the word on the screen at ground zero and replace it with a different word of the same length. What do you see? Just the new word, and with no sense at all of anything having been changed. As you peruse the text on the screen, it seems to you for all the world as stable as if the words were carved in marble, but to another person reading the same text over your shoulder (and saccading to a different drummer) the screen is aquiver with changes.
The effect is overpowering. When I first encountered an eye-tracker experiment, and saw how oblivious subjects were (apparently) to the changes flickering on the screen, I asked if I could be a subject. I wanted to see for myself. I was seated at the apparatus, and my head was immobilized by having me bite on a "bite bar". This makes the job easier for the eye-tracker, which bounces an unoticeable beam of light off the lens of the subject's eye, and analyzes the return to detect any motion of the eye. While I waited for the experimenters to turn on the apparatus, I read the text on the screen. I waited, and waited, eager for the trails to begin. I got impatient. "Why dont you turn it on?" I asked. "It is on," they replied.
I didn't mean "random" as in governed by an RNG, just "random" as in we can't obviously predict their pattern. The opposite of that would be being able to tell when they'll happen and where they'll end before they start, and/or make them happen on demand and land on desired target.
> We have had machines that do what you describe for decades.
I didn't knew that. Thanks for citation. This leads me to ask: so why aren't we employing this for VR?
It should be feasible to detect saccades instead of predicting them, and render new pixels more quickly than the eye can move. But it is right at the edge of what's possible, and really needs more reliable eye tracking than is generally available today, along with purpose built rendering techniques and higher resolution + higher field of view displays.
https://mailchi.mp/b4c8b26e025d/blindsight-project-update-se...
The difference in sensation of change was palpable.
Even though there's only 24 images on the film per second, this triple exposure results in a smoother experience for the viewer. This is due to how critical flicker fusion works (a.k.a. persistence of vision). [1] (Though another reason for doing it is simply so that the film won't be burnt, since those xenon gas projection lamps run very hot.) See also beta movement and phi phenomenon. [2]
These physiological phenomena are of course very important to consider when making VR devices and games.
In order to create the effect mechanically in the film projector, each frame has to be stationary before the shutter is opened. If not, all you'd see is a blur. Thus, when the film is pulled forward, the shutter blocks the light from projecting the image onto the screen. In fact, during some half of the movie, people are actually sitting is pitch black darkness. Think about that next time you go to the movies! ;)
Please note that peripheral vision has a higher sensitivity to flicker than foveal vision. I'm unsure how interlacing affects that, though, if applickable. This effect might also be different on video systems where various forms of interlacing may or may not be used.
[1]: https://en.wikipedia.org/wiki/Flicker_fusion_threshold
[2]: https://en.wikipedia.org/wiki/Beta_movement
(Please excuse my lack of sourcing. Most of this is off the back of my head, and from books I am no longer in posission of... But the Wikipedia links should give you a good start.)
Ironically, it sounds like a complement to saccades! Where saccades involve shutting off vision when your eye moves, this involves shutting off projection when the image moves.
MEMS kHz eye tracking enables even predicting where a saccade will land 20+ ms before: https://www.youtube.com/watch?v=JEg4l5KuQgI&t=452 (AdHawk @ AWE 2018).